The problem is, they didn't issue claims onto just videos showing of the game footage. If that was all they did it would have been fine. But they tried to flag people who just TALKED about the leaks. People sitting having a discussion with no footage at all. And that's what got people all riled up.Ehmm..okay but I assume these were more Sony's decisions than ND's. Make sense though that they want to protect their product before it's even out and not have it damaged by a disgruntled (ex) employee. Eventhough ofcourse one can argue if copyright claims are the appropriate method to contain that damage.
I am pretty sure Naughty Dog and Sony both issued copyright strikes against channels, I remember people reporting that from their youtube videos. Heelvsbabyface for one, and I think even Angryjoe had to deal with it. But certainly other smaller channels too, I guess they thought they could get away with silencing small channels because fuck the little people amiright?