Network-1 Technologies, Inc. v. Google LLC, Youtube, LLC

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
NETWORK-1 TECHNOLOGIES, INC.,
Plaintiff-Appellant
v.
GOOGLE LLC, YOUTUBE, LLC,
Defendants-Appellees
______________________
2024-1893, 2024-1948
______________________
Appeals from the United States District Court for the
Southern District of New York in No. 1:14-cv-09558-PGG-
SN, Judge Paul G. Gardephe.
______________________
Decided: April 23, 2026
______________________
BRIAN D AVID L EDAHL , Russ August & Kabat, Los
Angeles, CA, argued for plaintiff-appellant. Also
represented by MARC A. F ENSTER .
ANDREW V. T RASK, Williams & Connolly LLP,
Washington, DC, argued for defendants-appellees. Also
represented by XUN L IU; K EVIN HARDY , Quinn Emanuel
Urquhart & Sullivan, LLP, Washington, DC.
______________________
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 2
Before M OORE, Chief Judge, L OURIE and R EYNA, Circuit
Judges.
L OURIE, Circuit Judge.
Network-1 Technologies, Inc. (“Network-1”) filed suit
in the United States District Court for the Southern
District of New York, asserting that two separate versions
of Google LLC and YouTube, LLC’s (collectively, “Google”)
Content ID system infringed several claims of its U.S.
Patents 8,010,988 (“the ’988 patent”), 8,205,237 (“the ’237
patent”), 8,904,464 (“the ’464 patent”) (collectively, “the
asserted patents”). Network-1 Techs., Inc. v. Google LLC,
No. 14-cv-PGG-02396, 2024 WL 1814296 (S.D.N.Y. Apr.
24, 2024) (“Decision”). The district court issued a combined
claim construction and summary judgment decision. Id.
The court first determined that the asserted claims of the
’988 and ’464 patents are invalid as indefinite. Id. at *1. It
then determined that neither version of Google’s Content
ID system infringed the asserted claims of the ’237 patent
as a matter of law and thus Google was entitled to
summary judgment of noninfringement as to that patent.
Id.
Because a genuine issue of material fact exists as to
whether one version of Content ID infringes the ’237
patent, we reverse and remand as to that issue. We affirm
the district court’s conclusion of invalidity of the ’988 and
’464 patents for indefiniteness and grant of summary
judgment of noninfringement of the ’237 patent as to the
other version of Content ID.
BACKGROUND
I
Network-1 owns the asserted patents, which are
directed to methods for “linking traditional media to new
interactive media, such as that provided over the internet,”
and “identifying a work . . . without the need to modify the
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 3
work.” See ’988 patent col. 1 ll. 23–28.1 As an example, the
patent describes “[c]ommerce opportunities” where
television viewers could “place[] . . . direct orders for
products” they see on screen via an “interactive capability,”
i.e., an internet link to a website associated with the
specific product. Id. at col. 1 ll. 36–60. The asserted
patents facilitate this process by describing a technique for
identifying work (such as content or an advertisement)
without inserting an identification code, such as a bar code.
See id. at col. 1 ll. 25–28, col. 3 ll. 8–23, col. 4 ll. 7–19.
In relevant part, claims 15 and 17 of the ’988 patent
and claim 1 of the ’464 patent recite a method comprising
identifying an electronic work or correlating an electronic
work with an identifier via a “non-exhaustive search.” See
’988 patent col. 25 l. 65–col. 26 l. 6; ’464 patent col. 24 ll.
44–49.
In relevant part, independent claim 33 of the ’237
patent recites “[a] computer-implemented method
comprising . . . [a] determin[ation] by the computer
system, an identification of [a] media work using the media
work extracted features to perform a sublinear
approximate-nearest neighbor search of reference
extracted features of reference identified media works.”
’237 patent col. 28 ll. 5, 10–14 (emphasis added).
Google operates the website YouTube, which allows
users to upload content to the internet to be viewed by the
public. Decision, 2024 WL 1814296 at *3. Google employs
a “Content ID” system that allows content owners (e.g.,
copyright owners) to control how their content is used on
YouTube. Id. at *4. The Content ID system generates
matches by comparing an uploaded video, also known as a
“query work,” to a database of reference works. Id. There
1 We cite the ’988 patent as representative of the as-
serted patents’ specifications.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 4
are two versions of Google’s Content ID system at issue in
this appeal: an older version known as “LSH,” and a newer
version known as “Siberia.” Id.
The LSH version of Content ID works by searching
over an index of local sensitive hashing (“LSH”) bands, into
which “subfingerprints” corresponding to short snippets of
reference works are organized. Id. Subfingerprints for
query works and reference works are generated in the
same manner so that when a search is conducted for a
particular query work, the LSH version of Content ID
returns only the reference works associated with a
matching LSH band. Id. These reference works are then
further processed to eliminate candidates unlikely to be a
match with the query work. Id.
The Siberia version of Content ID works by generating
a sequence of embeddings corresponding to short snippets
or frames of content. Id. The reference embeddings are
further processed and stored in multiple reference indices
for searching, organized by content type. Id. at *5–6. Each
index is divided into smaller indices known as “shards”
that can each fit on one computer. Id. at *6.
II
In April 2014, Network-1 sued Google for infringement
of several claims of the asserted patents.2 Decision,
2024 WL 1814296 at *7.
In June 2015, Google petitioned the United States
Patent and Trademark Office Patent Trial and Appeal
Board (“the Board”) for inter partes review (“IPR”),
2 The original complaint asserted only the ’988 and
’237 patents. Decision, 2024 WL 1814296 at *7. Later in
2014, Network-1 asserted the ’464 patent in a related case,
which was consolidated with the original one. See 14-cv-
02396-PGG-sn, ECF 137–38.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 5
asserting that the ’237 and ’988 patents were unpatentable
as anticipated and obvious. See id. The district court
stayed the case pending resolution of the IPRs. Id. The
Board instituted the IPRs, and the proceedings before the
Board turned on the term “non-exhaustive search.” Id.
The Board found that Google had failed to carry its burden
of demonstrating the claims were not patentable. Google
LLC v. Network-1 Techs., Inc., 726 F. App’x 779, 780
(Fed. Cir. 2018) (“IPR Appeal Decision”). Google appealed,
and we vacated and remanded the Board’s decision because
it erred in its construction of “non-exhaustive search.” Id.
at 787. Using the broadest reasonable construction
standard, we construed “non-exhaustive search” as “a
search that locates a match without conducting a brute-
force comparison of all possible matches, and all data
within all possible matches.” Id. at 786.
In January 2019, the Board terminated the
proceedings on remand upon joint stipulation of the
parties. Google, Inc. v. Network-1 Techs., Inc.,
No. IPR2015-00343, 2019 WL 104044 (P.T.A.B. Jan. 4,
2019). Following the Board’s decision, the district court
lifted the stay in this case and the parties narrowed the
claims to claim 17 of the ’988 patent; claims 1, 8, 10, 16, 18,
25, 27, and 33 of the ’464 patent; and claims 33–35 of the
’237 patent. See Decision, 2024 WL 1814296 at *9, 11.
In April 2024, the district court published a combined
claim construction and summary judgment order disposing
of all asserted claims. Id. at *38. It concluded that the
term “non-exhaustive search” recited in the asserted
claims of the ’988 and ’464 patents was indefinite,
rendering those claims invalid. Id. at *20. The district
court also granted summary judgment of noninfringement
of the asserted claims of the ’237 patent, concluding that
there was no genuine issue of material fact that Google’s
LSH and Siberia Content ID systems met the “sublinear
search” limitation. Id. at *34, 38.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 6
Network-1 timely appealed, and we have jurisdiction
under 28 U.S.C. § 1295(a)(1).
D ISCUSSION
Network-1 appeals the district court’s invalidity and
summary judgment determinations. See Open. Br. 26–27.
We address each in turn.
I
Patent claims must “particularly point[] out and
distinctly claim[] the subject matter” regarded as the
invention. 35 U.S.C. § 112 ¶ 2. “A claim fails to satisfy this
statutory requirement and is thus valid for indefiniteness
if its language, read in light of the specification and
prosecution history, ‘fail[s] to inform, with reasonable
certainty, those skilled in the art about the scope of the
invention.’” Interval Licensing LLC v. AOL, Inc., 766 F.3d
1364, 1369–70 (Fed. Cir. 2014) (quoting Nautilus, Inc. v.
Biosig Instrs., Inc., 572 U.S. 898, 901 (2014)). Definiteness
is measured from the viewpoint of a skilled artisan “at the
time the patent was filed.” Nautilus, 572 U.S. at 908.
We review a determination of indefiniteness de novo.
Interval Licensing, 766 F.3d at 1370. Because “[g]eneral
principles of claim construction apply to indefiniteness,”
“we review a district court’s determinations of subsidiary
facts based upon extrinsic evidence for clear error, and
those based upon intrinsic evidence (the patent claims,
specification, and prosecution history) de novo.” HZNP
Medicines LLC v. Actavis Lab’ys UT, Inc., 940 F.3d 680,
688 (Fed. Cir. 2019) (citing Biosig Instrs., Inc. v. Nautilus,
Inc., 783 F.3d 1374, 1377–78 (Fed. Cir. 2015)).
The claims of the ’988 patent, which are representative
of the asserted claims of both that patent and the ’464
patent for purposes of analyzing the indefiniteness inquiry,
see Open. Br. 25, read as follows:
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 7
15. A method for associating an electronic work
with an action, the electronic work comprising at
least one of audio and video, the method
comprising:
a) electronically extracting features from
the electronic work;
b) electronically determining an
identification of the electronic work based
on the extracted features, wherein the
identification is based on a non-exhaustive
search identifying a neighbor;
c) electronically determining an action
based on the identification of the electronic
work; and
d) electronically performing the action.
17. The method of claim 15, wherein the non-
exhaustive search is sublinear.
’988 patent col. 25 l. 65–col. 26 l. 9; id. col. 26 ll. 14–15
(emphases added).
Network-1 submits the following construction for “non-
exhaustive search” in contending that the term is not
indefinite: “a search designed to locate a [near] neighbor
without comparing to all possible matches (i.e., all records
in the reference data set), even if the search does not locate
a [near] neighbor.” Open. Br. 52. Google submits that the
district court was correct and the term is indefinite. Resp.
Br. 21. We conclude that the district court correctly
determined that the “non-exhaustive” search limitation is
indefinite.
We begin with the claim language. Claims 15 and 17,
taken together, refer to a “non-exhaustive search
identifying a neighbor” which can be “sublinear.” ’988
patent col. 26 ll. 5–6, 14–15. Other than demonstrating
that “non-exhaustive searches” do not inherently identify a
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 8
neighbor (i.e., a close match) or are sublinear, the scope of
that language sheds little light on how a skilled artisan
would understand this term.
The written description also does not inform a skilled
artisan as to the scope of “non-exhaustive search” with
reasonable certainty. Our previous analysis of the term
from the IPR Appeal Decision, although not binding, is
informative. See 726 Fed. App’x at 786. There, Network-1
argued that the written description of a materially similar
patent reasonably conveyed the scope of the term because
it differentiated between “exhaustive searches” and “non-
exhaustive searches” because it “identifie[d] ‘a linear
search of all N entries’ as an ‘exhaustive search’” and
“[o]ther forms of matching,” such as “those based on
clustering, kd-trees, vantage point trees and excluded
middle vantage point forest,” as “non-exhaustive searches.”
Id. at 784–85. We rejected that argument because the
written description did not “draw a clear line between
‘exhaustive’ and ‘non-exhaustive’ searching in terms of how
much data within a record a search must consider in order
to qualify as one or the other.” Id. at 785 (emphasis added).
That same reasoning applies here. Network-1 argues
that column 9, lines 24–32 of the written description
informs a skilled artisan as to the scope of “non-exhaustive
searches” with reasonable certainty. Open. Br. 52–53. But
that language fails to do so. The written description does
not contain the terms “exhaustive” or “non-exhaustive,” but
instead contrasts “linear search[es]” which “can be
computationally very expensive” with “[o]ther forms of
matching,” including “kd-trees, vantage point trees and
excluded middle vantage point forests.” ’988 patent col. 9
ll. 24–30. Although the written description refers to a
“linear search,” nothing in the written description suggests
that a skilled artisan would understand a “linear search”
to be interchangeable with a “non-exhaustive search.” Nor
does it inform a skilled artisan with reasonable certainty
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 9
as to how much data within a record the “non-exhaustive
search” must consider.
Indeed, the phrase “non-exhaustive search” appears
nowhere in the original patent application that led to the
’988 and ’464 patents, but rather was added to the claims
nine years after the filing of the provisional application and
three years after the patent filing date which contained the
“linear search” language, in part to overcome prior art. J.A.
3245–53; see J.A. 79. To narrow “non-exhaustive search”
based on the “linear search” language used in the written
description would thus be to “view[] matters post hoc”––a
practice the Supreme Court has admonished. See
Nautilus, 572 U.S. at 911–12 (“[T]he definiteness inquiry
trains on the understanding of a skilled artisan at the time
of the patent application.”). It does the patent system or
the public no favor for this court to accept the
distinguishing of prior art with vague language that only
results in the uncertainty illustrated by this appeal and
this case’s long history.
Furthermore, the publications incorporated by
reference into the written description do not meaningfully
narrow the scope of “non-exhaustive search.” See ’988
patent col. 7 ll. 37–43, col. 9 ll. 32–38. The works cited––
Duda & Hart,3 Fukunaga,4 and the Yianilos papers5––
either make passing references to an “exhaustive search”
3 Richard O. Duda & Peter E. Hart, Pattern Classifi-
cation and Scene Analysis, Stanford Research Institute
(1973), J.A. 2830–31, 2871–72.
4 Keinosuke Fukunaga, Introduction to Statistical
Pattern Recognition (2d), J.A. 2912, 2961.
5 Peter N. Yianilos, Excluded Middle Vantage Point
Forests for Nearest Neighbor Search, NEC Research Insti-
tute (Aug. 1, 1999), J.A. 1400–11; Peter N. Yianilos, Locally
Lifting the Curse of Dimensionality for Nearest Neighbor
Search, NEC Research Institute, J.A. 1413–22.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 10
without any further information, see J.A. 2872 (Duda &
Hart), J.A. 2961 (Fukunaga), or conflict with Network-1’s
proposed “non-exhaustive searches,” see J.A. 1403–04
(Yianilos describing a vantage point forest search possibly
being “exhaustive”).
Even if the intrinsic record were not dispositive on its
own, the extrinsic evidence further supports a conclusion
of indefiniteness. The district court considered the
declaration of Dr. Michael Mitzenmacher, Network-1’s
expert witness, as well as several academic papers which
provided definitions of “exhaustive” versus “non-
exhaustive searches.” Decision, 2024 WL 1814296 at *15–
18; see J.A. 2764–95 (Mitzenmacher declaration). It
ultimately concluded that the extrinsic evidence did not
support Network-1’s construction but instead
“highlight[ed] the vague nature of ‘exhaustive search’ and
‘non-exhaustive search.’” Decision, 2024 WL 1814296 at
*18.
We find no clear error in the district court’s analysis.
Mitzenmacher’s declaration simply repeats the same failed
points above regarding the written description. See J.A.
2781–86. The declaration also relies on academic papers
Denny6 and Orwant.7 Id. at 2783, 2786–87. But these do
not inform a skilled artisan as to the meaning of “non-
exhaustive search.” Orwant states that “the definition of
exhaustive search is vague.” J.A. 3020. And Denny defines
a “non-exhaustive search strategy” as one that “traverse[s]
the search space more or less at random and thus certain
states may never be examined.” J.A. 3011. But as the
6 Paul C. Denny, Search and Enumeration Tech-
niques for Incidence Structures, Centre for Discrete Math-
ematics and Theoretical Computer Science (May 1998),
J.A. 3003, 3010–12.
7 Jon Orwant et al., Mastering Algorithms with Perl
(Aug. 1999), J.A. 3015, 3017–20.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 11
district court observed, this is inconsistent with Network-
1’s proposed construction because the proposed
construction does not have such a requirement to “traverse
the search space more or less at random.” Decision,
2024 WL 1814296 at *17.
Network-1’s argument to the contrary is unpersuasive.
It argues that our analysis of “non-exhaustive search” in
the IPR Appeal Decision should not inform our decision
here because it was under the broadest reasonable
interpretation (“BRI”) standard. Open. Br. 57–58. We
disagree. It is true that we utilized the BRI, not Phillips,
standard in the IPR Appeal Decision. See 726 Fed. App’x
at 786. But the analysis regarding the written
description’s lack of identification of “non-exhaustive
search” is the same––i.e., regardless of standard, the
written description does not draw a clear line between
“exhaustive” and “non-exhaustive.” See id. at 785.
In sum, neither the intrinsic nor extrinsic evidence
offers sufficient guidance to a skilled artisan as to the scope
of the term “non-exhaustive search” with reasonable
certainty. The asserted claims of the ’988 and ’464 patent
are thus invalid for indefiniteness.
II
We next consider the district court’s grant of summary
judgment of noninfringement of the ’237 patent.8 “We
review the district court’s grant of summary judgment
under the law of the regional circuit in which the court sits,
here, the Second Circuit.” See Medgraph, Inc. v. Medtronic,
8 Although the written description of the ’237 patent
includes the same disputed language regarding “linear
search” versus “other forms of searching,” ’237 patent col.
8 ll. 59–67, the definiteness of the asserted claims of the
’237 patent is not before us. We accordingly do not deal
with it here.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 12
Inc., 843 F.3d 942, 947 (Fed. Cir. 2016) (citation omitted).
“The Second Circuit reviews a grant of summary judgment
without deference, construing the evidence in the light
most favorable to the nonmovant and drawing all
reasonable inferences in that party’s favor.” Id. (citing
Kuebel v. Black & Decker Inc., 643 F.3d 352, 358 (2d Cir.
2011)). “Summary judgment may only be granted when no
‘reasonable jury could return a verdict for the nonmoving
party.’” Id. (quoting Anderson v. Liberty Lobby, Inc.,
477 U.S. 242, 248 (1986)).
“Summary judgment of noninfringement is
appropriate where the patent owner’s proof is deficient in
meeting an essential part of the legal standard for
infringement, since such failure will render all other facts
immaterial.” Telemac Cellular Corp. v. Topp Telecom, Inc.,
247 F.3d 1316, 1323 (Fed. Cir. 2001). “[I]n order for a court
to find infringement, the plaintiff must show the presence
of every . . . [limitation] or its substantial equivalent in the
accused device.” Wolverine World Wide, Inc. v. Nike, Inc.,
38 F.3d 1192, 1199 (Fed. Cir. 1994).
Claim 33 of the ’237 patent, which is representative for
purposes of analyzing summary judgment, reads as
follows:
33. A computer-implemented method comprising:
a) obtaining, by a computer system includ-
ing at least one computer, media work ex-
tracted features that were extracted from a
media work, the media work uploaded from
a client device;
b) determining, by the computer system,
an identification of the media work using
the media work extracted features to per-
form a sublinear approximate nearest
neighbor search of reference extracted
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 13
features of reference identified media
works; and
c) determining, by the computer system, an
action based on the determined identifica-
tion of the media work.
’237 patent col. 28 ll. 5–16 (emphasis added).
The parties’ dispute centers on whether the LSH or
Siberia versions of Content ID meet the “sublinear search”
limitation as recited in claim 33 of the ’237 patent. Open.
Br. 30; Resp. Br. 41. The parties agree that LSH or Siberia
meet the “sublinear” limitation if its “execution time scales
with a less than linear relationship to the size of the data
set to be searched, assuming computing power is held
constant.” Open. Br. 44; Resp. Br. 41; see also Decision,
2024 WL 18142962024, at *28. The district court
concluded that Network-1 did not create a material issue
of fact as to whether either version met this limitation and
thus granted summary judgment of noninfringement. Id.
at *34, *38. We address each version in turn.
A
We begin with the LSH version of Content ID.
Network-1 relied on three pieces of evidence in opposing
summary judgment before the district court: (1) the
academic work of Google research scientist Dr. Shumeet
Baluja (“the Baluja papers”) and his testimony; (2) a
Google 2010 draft document; and (3) Mitzenmacher’s
report. See Decision, 2024 WL 18114296 at *28. The
district court concluded that none of the three created a
genuine issue of material fact as to whether the LSH
version was sublinear. Id. at *34. After de novo review of
each, we agree with the district court.
The Baluja papers and his testimony do not create a
genuine issue of material fact. See J.A. 9690–9703 (paper
titled “Waveprint”); J.A. 9714–51 (paper titled “Learning
to Hash”); J.A. 7225–26, 7321–24, 7361–63, 7371–74,
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 14
7398–7400, 7403, 7406 (Baluja testimony). Network-1
argues that the papers contain statements which a
reasonable trier of fact could interpret to describe LSH
systems as sublinear. See Open. Br. 32–33. But neither
paper describes the LSH version of Content ID. See
generally J.A. 9690–703; J.A. 9714–51. Rather, they
describe a system called Waveprint, which uses computer-
vision techniques for identifying audio, see J.A. 9690, and
describe hash functions only generally without addressing
the LSH version, see J.A. 9716–18. And at his deposition,
Baluja confirmed that he was not involved in
implementation, but rather only research. J.A. 7399.
Network-1’s argument is thus unavailing, as there is
insufficient evidence connecting Baluja’s papers or
testimony to Google’s LSH version to create a genuine issue
of material fact.
The Google 2010 draft document suffers from a similar
flaw: there is insufficient evidence connecting it to the
implementation of the LSH version. Network-1 argues it
creates a genuine issue of material fact because it describes
Google’s matching infrastructure as having LSH tables
that will scale sublinearly. Open. Br. 34–35 (citing J.A.
9387). We disagree. There is no evidence in the record that
Google implemented such tables from the 2010 draft
document. Indeed, the document contemplates two types
of LSH tables: one that scales sublinearly and one that does
not. J.A. 9387. But Network-1 points to no evidence that
one was implemented over the other. See Open. Br. 34–36.
Rather, Network-1 is essentially arguing that Google was
capable of infringing the ’237 patent. But even with all
reasonable inferences in Network-1’s favor, there is no
evidence of what Google actually implemented to present a
genuine issue of material fact. See Miken Composites,
L.L.C. v. Wilson Sporting Goods Co., 515 F.3d 1331, 1340–
41 (Fed. Cir. 2008) (affirming summary judgment of
noninfringement when there was no record evidence of
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 15
literal infringement, even though the possibility of
infringement existed).
Finally, the Mitzenmacher report does not create a
genuine issue of material fact. Indeed, it relies
significantly on the Baluja papers, Baluja’s testimony, and
the Google 2010 draft document. See J.A. 6598–99. But as
we explained above, those do not create a genuine issue of
material fact because there is insufficient evidence
connecting them to the implementation of the LSH version.
Furthermore, Mitzenmacher’s review of Google’s code does
not demonstrate that the LSH version is sublinear; it
rather steps through the process of the content
identification without any analysis as to how it is
sublinear. See J.A. 6599–6602. Because Mitzenmacher’s
report contains no other support, it does not create a
genuine issue of material fact. See Minkin v. Gibbons, P.C.,
680 F.3d 1341, 1352 n.5 (Fed. Cir. 2012) (“It is well-
established that unsupported expert opinions do not create
a genuine issue of material fact.” (citations omitted)).
In sum, no piece of evidence considered by the district
court, and which Network-1 relies on before us, creates a
genuine issue of material fact. Google is thus entitled to
judgment as a matter of law of noninfringement of the ’237
patent as to the LSH version.
B
We next consider the Siberia version. The district
court granted summary judgment of noninfringement
because, in its view, the evidence indicated that the Siberia
version did not scale sublinearly. See Decision, 2024 WL
1814296 at *36.
Upon de novo review, we conclude that there is a
genuine issue of material fact regarding the Siberia version
so as to preclude summary judgment of noninfringement of
the ’237 patent.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 16
First, there is a fundamental dispute as to how the
Siberia version functions. Network-1 argues that the
Siberia version is sublinear because the algorithm has
different “tunable knobs,” which Google adjusted to lower
resource costs. See Open. Br. 45–47 (citing J.A. 9812; J.A.
10395–96). Google counters that the Siberia version is
undisputedly linear because it “search[es] a fixed fraction
of the data set.” Resp. Br. 54 (citing J.A. 3953). And it
further argues that “[e]ven if Google reduced the number
of searched [components], Siberia would still search a
predetermined proportion of all partitions and thus scale
linearly.” Id. at 60 (citing J.A. 4447–48).
We conclude that this dispute is best left to a factfinder.
With all reasonable inferences in Network-1’s favor, a
factfinder could find that the Siberia version as an overall
system was designed to have an execution time which
scaled in less than a proportional relationship to the size of
the reference set because the “tunable knobs” allowed the
system to adapt to a growing dataset size. See J.A. 9812;
J.A. 10335; J.A. 10378–79; J.A. 10395–96. For purposes of
summary judgment, it is immaterial that the Siberia
version, once that “knob” is turned, may search that new
“fixed fraction” linearly.
Furthermore, an internal Google document regarding
the Siberia version states that Google “will need . . . a
sublinear search.” J.A. 10265 (emphasis added). That is
also enough to create a factual issue; with reasonable
inferences in Network-1’s favor, a factfinder could consider
this document to describe the implementation of the
Siberia version as sublinear. Google argues this document
“is referring to a potential strategy, not Siberia as
implemented.” Resp. Br. 56. That argument is
unpersuasive. A factfinder could reasonably read the
phrase “will need” as imposing a requirement of a
sublinear search on any future Siberia implementation.
J.A. 10265. It thus creates a genuine issue of material fact
regarding whether the Siberia version is sublinear.
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NETWORK-1 TECHNOLOGIES, INC. v. GOOGLE LLC 17
Because there is a genuine issue of material fact,
summary judgment of noninfringement of the ’237 patent
as to the Siberia version is inappropriate.
CONCLUSION
We have considered the remainder of the parties’
arguments but find them unpersuasive. We reverse the
district court’s grant of summary judgment of
noninfringement of the ’237 patent as to the Siberia version
of Content ID and remand for further proceedings. We
affirm the district court’s conclusion of indefiniteness as to
the ’988 patent and ’464 patent. We affirm the district
court’s grant of summary judgment of noninfringement of
the ’237 patent as to the LSH version of Content ID.
AFFIRMED IN PART, REVERSED IN PART, AND
REMANDED
COSTS
No costs.
Case: 24-1893 Document: 69 Page: 17 Filed: 04/23/2026

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