Beijing Meishe Network Technology Co., Ltd. v. TikTok Inc.

Background

Beijing Meishe Network Technology Co., Ltd. filed six motions seeking to exclude expert testimony, and the defendants filed three. The court held a hearing on August 29, 2025. The motions addressed expert opinions concerning alleged copying of source code, copyright infringement, trade-secret misappropriation, damages, Chinese copyright and contract issues, software development, and trade-secret protection.

Under Federal Rule of Evidence 702, expert testimony must be relevant and reliable, based on sufficient facts or data, and produced through reliable methods reliably applied to the case. The court’s role is to act as a gatekeeper, but weaknesses that can be explored through cross-examination generally affect the testimony’s weight rather than its admissibility.

Defendants’ Motions

Yanfang Wang. The defendants did not file a formal motion against the report of Chinese Judge Yanfang Wang, but they argued in a reply brief that the report should be excluded because Judge Wang did not sign it under penalty of perjury. The court declined to exclude the report, noting that the defendants had not given Beijing Meishe an opportunity to respond through a Daubert motion and that Judge Wang provided sworn deposition testimony about the report.

Michael Shamos. The defendants’ motion concerning Dr. Michael Shamos was granted in part and denied in part. Dr. Shamos may testify about copying in versions of TikTok’s code beyond the three versions he specifically reviewed if Beijing Meishe lays a sufficient foundation during examination. He may describe code similarities and testify about his opinion that the defendants copied Beijing Meishe’s code, but he may not call TikTok code a “derivative work” or label the codes “substantially similar,” because those are issues for the jury. He may not introduce evidence about the protection measures Beijing Meishe took to protect its trade secrets, although he may discuss the adequacy of measures established in the record by fact witnesses if a foundation for his expertise is established. He also may not state, in the conclusory form offered in his report, that the code “clearly has economic value.”

Dr. Shamos may reference Exhibit D to his report, but he may not use it as a basis for additional code comparisons. He may discuss the exhibit’s creation and information apparent from the exhibit itself, but he may not offer additional text-to-text comparisons beyond those in the other exhibits to his report.

Sam Malek. The defendants’ motion concerning Dr. Sam Malek was denied. The court held that defendants’ objections to his method of estimating the value added by Beijing Meishe’s allegedly stolen intellectual property went to the weight of his testimony, not its admissibility. Dr. Malek may also testify about the reverse-engineering project conducted by the defendants’ expert, Anthony DeRosa, but only to critique that project; he may not offer other testimony about whether Beijing Meishe’s trade secrets were readily ascertainable.

Jonathan Putnam. The defendants’ motion concerning Jonathan Putnam was denied. The court found that concerns about the reliability of Business of Apps data and Putnam’s damages calculations could be evaluated by the jury. The court also declined to require advance apportionment of damages among the asserted trade secrets because the number of trade secrets was smaller and the asserted secrets were closely related. The court likewise declined to exclude Putnam’s report because it lacked a sworn declaration.

Plaintiff’s Motions

Xiangjun Kong. Beijing Meishe’s motion concerning former Chinese Judge Xiangjun Kong was denied. The court found that Kong’s report was based on a sufficient factual foundation despite his not reviewing certain licensing agreements and his statement that he had read the relevant portions of Chinese court opinions. The court also held that defense counsel’s assistance in drafting the report did not make it unreliable because Kong supplied his opinions, reviewed and modified the draft, and testified that the report contained his opinions and viewpoints.

Nigel Jones. Beijing Meishe’s motion concerning Nigel Jones was granted in part and denied in part. The court found that Jones’s sampling methods could be understood and evaluated by a jury and that objections to his analysis of individual code elements concerned weight rather than admissibility. Jones may testify about interpreting particular entries in Subversion program logs, but he may not opine on how those entries fit with or contradict other evidence. He may not testify about software versions that Beijing Meishe previously asserted but later dropped from the lawsuit. His comparison involving the code submitted for the one registered Chinese copyright was admissible for determining which code version corresponded to that copyright, but it did not bear on Beijing Meishe’s asserted unregistered copyrights. Jones may not offer legal conclusions, including whether the codes are substantially similar or whether the defendants are entitled to a fair-use defense. On the disputed fair-use issue, the court adopted Beijing Meishe’s interpretation that “the portion used” is not limited to protectable expression.

Kevin Almeroth. Beijing Meishe’s motion concerning Kevin Almeroth was granted in part and denied in part. Almeroth may testify about the details of his analysis of trade-secret misappropriation or the absence of misappropriation, but he may not state the legal standard for misappropriation or offer legal conclusions. The court and the parties would address the correct legal standard through jury instructions.

John Kelly. Beijing Meishe’s motion concerning Dr. John Kelly was denied. The court found that objections to the methods and possible contamination of Kelly’s “clean room” software-development project went to the weight of his testimony. Kelly may testify about his estimate of the time and cost of creating a replacement software kit, even though the project did not itself fully develop a replacement application.

James Pooley. Beijing Meishe’s motion concerning James Pooley was denied in part and granted in part. Pooley may testify based on his expertise as an information-security consultant, rather than as an attorney. If the defendants establish relevant experience with software companies, he may discuss protective measures he has advised clients to use, measures he would advise a company like Beijing Meishe to use, and whether the evidence aligns with industry standards. He may not explain trade-secret law, conclude that Beijing Meishe did or did not take “reasonable measures,” discuss the discovery history, or merely repeat other experts’ statements without independently evaluating them through his own expertise.

David Teece. Beijing Meishe’s motion concerning Dr. David Teece was denied in part and granted in part. Teece may testify about statistical tests applied to Dr. Putnam’s analysis if he can adequately explain how those tests work. Challenges to his calculation of incremental costs went to the weight of his testimony. Teece may rely on other admitted expert testimony, but he may not offer his own opinions on technical matters outside his expertise; any reliance on another expert’s testimony must be expressly stated.

Conclusion

The court stated that the motions to exclude the reports and testimony of Sam Malek, Jonathan Putnam, Xiangjun Kong, and John Kelly were denied. The motions concerning Michael Shamos, Nigel Jones, Kevin Almeroth, James Pooley, and David Teece were denied in part and granted in part, as explained in the order. The trial remained scheduled to begin on October 27, 2025, with the pretrial conference scheduled for October 14, 2025.