you accidently throw your diamond out of your inventory and someone else takes it

dogs/cats take all you bones/fish like 10 of them and runs away

your in flatland building the best city ever when a slime killed you and you can never find your awesome city

people ban you just to let his or her friend play in the server

someone pushes you in lava

trolls tnt your things

you get greifed

someone pushes you in a pvp aloud area and kills you