4chan

Here you have the link

http://www.4chan.org/

I actually didn't browse in this page, but there can be many of horror things deep inside, if you have enough time - you can explore it, maybe you find anything horrible, and if so, you can comment it and share for the audience!))

There are a lot of things that came from 4chan, like those photos of naked celebrities xD i don't know if they are really from 4chan, but this site is really deep and interesting. Actually there were many of real happenings, like murders and suicides that those people have posted there. 

For more information, you can search for videos in youtube or explore it by yourself, that will be more exciting !! xD