as far as most disturbing thing to watch, probably the self-immolation of aaron bushnell back in february. i generally avoid the more messed up infamous internet stuff.

eta: more disturbing, but not quite as punchy due to not being a video, was a post i saw once about a young lady who picked at her legs so much, that they had to be removed. there was a lot of pictures. she eventually dug a hole straight through them.