Website Slackstory has put together some of the most disturbing stories that people wrote on a "What's your secret that could literally ruin your life if it came out?" thread on Reddit. Yes, it's horrible to read about people who have killed (accidentally and purposely), stolen or engaged in generally fucked up, immoral behaviour (just search for "cum box" in that article to see what I mean). And yet, I can assure you, you will keep reading, totally fascinated by the human condition all around us.
I basically killed my father. or at least intentionally allowed him to die.
He was an abusive father all my life, and when I was 19, he had a heart attack. I calmly took the phone away from him before he could dial 911, put the recliner he was sitting in up so he would be laying back and his weight would make it harder to breathe, took one last look right at him, then left the room.
About an hour or so later I found him sitting there staring forward with foam in his mouth, not breathing.
I should clarify that I had been working at a hospital for at least 4 years at that point (volunteer work) and I was first aid certified. I knew exactly what was happening, and what I was doing.