I've been lucky, I suppose. Having first gotten my hands inside a computer (and actually gotten it working) at the age of 10 (not that long ago, mind you, I only turn 18 next month), and started programming a couple years later, I've heard tales of such legal trouble, and carefully scoured all contracts I've signed with companys for anything vaguely relating to IP ownership. I've been lucky enough to find nothing (mostly because they were small, local companies who don't really care).
It's too bad this had to be applied to tilly, though. Such a great member of this community. His contributions will be greatly missed.
Note: Since this has been linked to on /., I'm hosting a mirror (with permission from 2 of the gods, and several pmdev'ers) which /. is linking to instead of PM for a few days so the Monestary doesn't get nailled by traffic it can't handle. I'll find out tomorrow morning just how smart I was to throw myself in front of a speeding /., as boo_radley put it.