The first one was on my starting day. While showing me around the systems, he sat down at my PC and sent a vicious email, using _my_ account, to another group that I'd need to be on good terms with. I immediately had to go to them and diplomatically explain that I was not the one that wrote the email.

There were many other such instances, most worse and that were direct attacks against me. I probably could have won a lawsuit, but that's foolishness. If you're in a situation like that, run away as fast as you can!