I remember that once, a Facebook page was hacked into (I guess) and started posting pictures and stories about tortured animals. Everybody went WTF and the page was shut down a few days later.

4chan all just like animals

I've never been there, but plenty of people on the internet do. Facebook pages against vivisection etc. seem to get way more likes than those in favour of it, the meme that humanity had better become extinct because wildlife would be better off is quite widespread, and some people even rejoice when a hunter dies (though this is a minority stance).