Your conclusion is nonsensical; WebM has nothing to do with search or personal data.
Adobe Flash is a well-adopted de facto standard that they can't just drop (particularly given that one of their properties relies heavily on it). Native h.264 isn't widely adopted yet and, thus, doesn't have that problem.
GIF and JPEG are also well-adopted standards that would have the same problems. The patents on GIF have already expired though, so there's no openness issue there. I'm not well-informed enough to speak on the patent status of JPEG.
The claim about their browser is also absurd. If everyone supported WebM, their browser would have no advantage in the marketplace. People generally don't adopt a browser simply because its native codec support either.
If you want to make the conclusion that Google is doing this for financial reasons, you really need to look no further than YouTube. It wouldn't be at all surprising if they want to avoid shelling out to MPEG LA should they decide to collect patent royalties from Google in the future.
According to Wikipedia, the ACLU-related person on the Supreme Court is Ruth Bader Ginsburg: "General Counsel, American Civil Liberties Union (1973-1980)" ; thought I'd mention this since a search for "ACLU solicitor general" turns up nothing.
Real programs don't eat cache.