Honestly, that didn't help. There's a wide type of "controversy" there, and I don't see how 4chan are inherent to any of them, they could've been done via any forum. Or maybe I missed something, specificity would be good.

But they weren't done via any forum, they were done via 4chan. The community makes a forum.

It's a well known forum with a lot of users, to blame the "4chan community" would seem to be either a fallacy of composition or, ironically, of division, depending how the claim is laid out.

I'm also not sure how the site admins would stop them?