[Closed] Worst thing you ever came across on the T'internet?

I foolishly opened a link to a video in a mail sent to me from an unknown email address (stupid I know!). Thankfully it wasn't a virus that ate my computers insides but an actual video of the most horrific thing I think I have ever seen. It literally made my toes curl.

I won't go into too much detail but in a nutshell male films himself sitting on a glass jar, inserting it and said glass jar then breaking into many pieces followed by much gushing of blood and sound of broken glass crunching around inside. Utterly horrific.

So, with so much horrible stuff on the net, what is the worst most regrettable thing you have come across?