My little brother, 12, has a 60l tank and 3 goldfish. I have told him its too small etc etc etc...
Today, he decided he wants some more "fancy" fish. So he went and bought himself 5 mountain minnows.
Well, we come back to the tank an hour later, to find 1 dead and the other 4 being chased like crazy. THEY WERE BEING EATEN! As I watched the entertaining show, my little brother is yelling and whacking on the glass whenever the goldfish got too close. My mum then told him to get a little plastic tank from below to hold them in. Even while he was fishing them out, the goldfish were still going for them!
He is horribly neglectful to the fish, but I found it funny and I thought he needed to learn he needs to research the fish the hard way.
Just thought I'd share the highlight of my day. 8)