I know you mean I had many instances in Minecraft that made me stop playing for a few days.
One time I was playing offline on the 360. So that meant I was by myself, not gonna lie I was playing in creative mode because I love building random things. Anyway at one point I got messages saying "Go Away" and "Leave me alone" I remember sitting down some glowstone then being sent spiraling through the sky! I died the pop up message said "Arekusu was killed by "
Another time that made me furious was when I played multiplayer on the computer. I was with my friends and it was my first time playing Minecraft and I had just learned to get a dog. I named him Oliver. Several months past and me and my friends were making a world to post to the servers. Well later that week we logged on and noticed the world was in ruins! We were confused as to who did this but chose to not complain and just fix the mess.
Once everything was fixed we continued to work on the world with help from other players. As we worked we noticed that there was an Enderman just standing there. And if we went somewhere it would follow us, this happened for several weeks until one day one of my friends typed "Geez, dat Ender is a freak...it's always here"
Well without warning the Enderman took out and placed down several TNT and blew up the spot my friend was working killing him! The Ender then banned my other friends and killed me and Oliver! Its was some jerk Minecraft admin who later had the nerve to post "Enjoy MC"