My art teacher stole a painting I've been working on and painted over it. It was for the Memory Project, which allows art students to create unique portraits as gifts for orphaned children all over the world. I've been working on my for a while and was about to the point where I could honestly and resolutely say I was done. Then, it disappeared from the art room for a few weeks and returned looking like a portrait of a chipmunk with FAS. %)!@(
She also told me that I won't succeed in college... and that I should incorporate text into my artwork ("you should incorporate text in that" is the second thing out of her mouth during crit.). She's well... to put it lightly, a fucking cunt.
Then again, I'm sure everyone has had their fair share of art teacher horror stories.