Technology and Internet Evidence in Chinese Patent Invalidation

By Linna Song

Introduction

In Chinese patent litigation, two of the most common defenses raised by alleged infringers are non-infringement and patent invalidity. Of these, invalidating a patent is often the most effective “root solution,” removing the legal foundation of an infringement claim altogether.

But what evidence can actually be used to prove invalidity? Beyond traditional materials like prior patents, technical manuals, or academic publications, internet-based materials (such as WeChat posts, online forums, YouTube videos, or social media content) are increasingly submitted as prior art. This trend reflects the digital reality of how technology is shared, but also raises complex evidentiary challenges, especially regarding publication time and content authenticity.

This article highlights the main categories of invalidation evidence under Chinese law, the special issues surrounding internet-based evidence, and practical tips for both international and Chinese businesses engaged in patent disputes.

1. Evidence Types in Patent Invalidation

Chinese law recognizes several categories of evidence to challenge a patent:

• Conflicting applications: Earlier-filed patent applications in China, disclosed after the filing date but with an earlier priority. These are used only to assess novelty.
• Prior art / prior designs: The broadest category, covering technology made publicly available anywhere in the world before the filing date, whether through:
  • Publication (patents, journals, books, technical manuals, online articles)
  • Use (sales, exhibitions, demonstrations)
  • Other disclosures (broadcasts, presentations, oral communications)

In practice, the vast majority of invalidation proceedings rely on published evidence, as it provides verifiable dates and content.

2. The Rise of Internet-Based Evidence

With the explosion of digital platforms, the internet has become a valuable source of potential prior art. Photos, videos, and posts on WeChat, Weibo, YouTube, Facebook, and other platforms may reveal product designs, technical features, or even full operating principles.

Why it matters: Many technologies are widely known and used in practice but may never have been patented or formally published in academic sources. Internet postings often become the only available documentation of such knowledge.

3. The Key Challenge: Proving Publication Date

The critical weakness of internet evidence is its publication date. Courts and the CNIPA require proof that the material was publicly available before the patent’s filing date. Without reliable dating, the evidence cannot serve as prior art.

• Evidence with timestamps: WeChat articles, Weibo posts, news pages, YouTube uploads, etc. These usually show a publication date automatically.
• Evidence without timestamps: Product listings (which sellers can edit), company websites, or standalone images. These are often rejected unless supported by additional evidence.

Even when a timestamp exists, courts scrutinize whether the platform allows post-publication edits that could alter content without updating the date. For example:

• YouTube videos can be uploaded privately and later made public without changing the “published” date.
• Facebook images can be replaced while retaining the same timestamp.

Such editing functions undermine the reliability of timestamps unless corroborated by further evidence.

4. Judicial Practice: Strict Standards Emerging

Recent Chinese court rulings, including those from the Supreme People’s Court, illustrate a tightening approach:

• Courts require a “high probability” standard that the evidence was indeed public at the indicated date.
• When platforms allow edits without date changes, the burden shifts to the invalidation petitioner to provide supplementary proof such as platform rules, technical reports, or independent tests showing the date cannot be falsified.
• In some cases, courts have accepted YouTube or Facebook evidence when accompanied by explanations of the platforms’ mechanisms. In others, they have rejected it for lack of sufficient corroboration.

This divergence highlights the evolving, fact-specific nature of internet evidence assessment in China.

5. Practical Guidance for Businesses and Legal Teams

For those challenging a patent (petitioners):

• Don’t stop at screenshots. Collect supporting material such as platform policies, service terms, or independent tests, that explain how publication dates are generated and whether they can be altered.
• Chain the evidence. Combine internet materials with other sources (advertising brochures, archived webpages, or contemporaneous industry reports) to reinforce credibility.
• Anticipate challenges. Assume the opposing party will contest authenticity and timing, and prepare counter-arguments upfront.

For patent owners defending against invalidation:

• Target the timestamp. Question whether the platform allows edits without visible trace.
• Demand corroboration. Argue that, without supporting documentation, internet evidence does not meet the high-probability standard.
• Highlight alternative explanations. Suggest that evidence may have been manipulated or selectively disclosed.

6. Why This Matters for International Companies

For multinational businesses operating in China, this issue has two major implications:

1. Risk management: Products promoted online may unintentionally create prior art that undermines future patent filings. Timing and content control of digital marketing should be coordinated with IP strategy.

2. Dispute strategy: In litigation, the ability to leverage internet-based prior art may be decisive, particularly in fields where formal publications lag behind industry practice.

Conclusion

Internet evidence has become a powerful yet double-edged tool in Chinese patent invalidation proceedings. While it expands the range of prior art beyond traditional publications, its admissibility hinges on the reliability of publication dates and the robustness of supporting proof.

For both challengers and right holders, the lesson is clear: the evidentiary battle increasingly lies not in the technology itself, but in proving whether the digital record can be trusted.

As Chinese courts and the CNIPA continue to refine their standards, companies must adapt by integrating legal, technical, and digital expertise into their patent strategies, ensuring that their rights are both defensible and enforceable in an internet-driven world.