I had Piranha's and I hated seeing feeder fish floating around with their guts hanging out. The Piranha's just would not eat the rest. I stopped feeding them, thinking they would finish up the half alive feeder fish. No such luck, they just chewed each others tails off. What a mess, what a stink, what a bother.

I released them in a creek,
Don't worry, they are warm water fish and probably died in the winter. They were fairly small and could not really have injured a human.

They are definitely not like in the movies.