Swift and predictable reactions to WebM

One thing that occurs to me: I have seen a lot of speculation and commentary on whether Google has done sufficient due-diligence with respect to the question of whether VP8 infringes on any MPEG-LA patents, but not much about the reverse question.

Between competing corporations patents tend to be something that they horde so that they can be used in defensive "mutually-assured-destruction" threats - "if you don't attempt to enforce patent X against us, we will not attempt to enforce patent Y against you ...".

On2 have been in the video codec business for a while now. I wonder if Google have inherited any On2 patents that could be used to put the thumbscrews on H.264, or other portfolios that MPEG-LA care about ... ?