There is a lot of horrifying content out there. Videos of people brutally murdering others are probably among the top imo.

Something that I had a hard time physically looking at was I once stumbled across a man who appeared to be having some sort of psychotic episode. He filmed himself trying to pull a microchip out of his eye. He kept picking at it and gouging it with his bare hands. I don't understand how he was able to do that without screaming in pain. Hope the poor man got better after but who knows what happened.

Edit: And before anyone attempts to ask...no I don't have a link. LiveLeak was where I had seen a lot of things and it doesn't exist anymore. I'm sure there are a myriad of other sites out there if you're morbidly curious. Just don't go asking me for references. Like others said...for many people it can end up messing them up. Don't show anything to anyone else. If you are curious and you think you can handle it, then that's on you. But don't make anyone else see it even if they say they are ok with it.