The Federal Circuit recently upheld two patents against an obviousness challenge by Google. (Google v. At Home Bondholders Liquidating Trust (Fed. Cir. 2018).) This case demonstrates the importance of contemporary evidence to support what a piece of prior art truly would have disclosed to a person of ordinary skill in the art.
At Home Bondholders’ Liquidating Trust, as the name indicates, formed from the ashes of a practicing entity. As part of monetizing the leftover assets, At Home sued Google for infringing U.S. Patent Nos. 6,014,698 and 6,286,045. Google responded with two inter partes review petitions against each of the patents.
The Patent Trial and Appeal Board focused on one limitation common to all the challenged claims, that an advertising request is nonblockable. When a user requests a webpage, the webpage and corresponding banner ads are cached at an intermediary server, and if the user requests the same webpage, the webpage and banner ads are delivered from the intermediary server. But the website may not get an accurate count of how many times the banner ad is loaded because it doesn’t see those multiple requests from the user. The patents solve that problem by specifying that a first request for a banner ad is nonblockable by the intermediary server. One example in the specification is to include the strings “?” and “cgi-bin” in the URL, making the request dynamic and thus “unsuitable for caching.”
Against that limitation, Google used the same reference against all the claims, U.S. Patent No. 5,933,811 to Angles. Angles disclosed an advertising request referencing a Common Gateway Interface (“CGI”) script. Google argued that, because CGI scripts are nonblockable by default, a person of ordinary skill in the art would have understood Angles to disclose a nonblockable advertising request.
But the PTAB instead credited At Home’s argument that a person of ordinary skill would not have understood Angles to disclose a nonblockable advertising request because CGI scripts are not necessarily blockable. To back up its point, At Home presented two contemporary sources on the understanding of a person of ordinary skill in the art, a CGI programming textbook and a publication by the World Wide Web Consortium, which both gave examples of blockable CGI requests. To explain the argument, At Home used expert testimony that relied partly on the two contemporary sources. The Federal Circuit found no error in the PTAB’s reasoning.
Lessons for Practice
As the Federal Circuit helpfully noted, “Obviousness is a question of law based on underlying factual findings.” And what helps support factual findings? Evidence. Google may have thought that unearthing a reference showing, essentially, one of the embodiments of the claims would be enough to carry the day. But actual contemporary references showing blockable CGI requests, along with some persuasive testimony, turned the case around, convincing the PTAB that a person of ordinary skill in the art would have considered it quite normal to deviate from the default setting for CGI scripts. Determining validity over prior art is often a sort of historical expedition—in this case, back to the 90s—and contextual evidence contemporary to the challenged patent can be invaluable.
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