I suspect that for a lot of those it's a case of "the development guys want to use this open source library" and nobody in legal has ever been asked. For large

I suspect that for a lot of those it's a case of "the development guys want to use this open source library" and nobody in legal has ever been asked. For large companies this is likely an annoyance move, with the argument that nobody who chose to use it is authorized to make that kind of patent - related agreements any more than they're authorized to sell office buildings or manufacturing facilities, but for small tech startups of the sort that Facebook once was this may be a huge hammer.