And that's why nobody sane will try to screw with them. Nobody wants to lose the ability to do video on the internet during next 20 (plus/minus) years.
That "We may have stolen your technology" is pushing it.
Google did due diligence before buying On2 with VP8. They did patent search. If anyone appears now with some patent claim against VP8, suing left and right users of VP8, it does not show good faith on their part.
Google's position is literally... screw with us, and if WebM catches on, you can't do video on the internet.