http://news.yahoo.com/blogs/sideshow/student-returns-half-billion-dollar-check-213623198.html I think if that was me, I would take a shot at keeping it. I would buy a 30 year t-bond with the $690 million and wait for the government to come looking for it and say "Hey, I was helping keep interest rates low for you guys...here is the bond with the full $690 million back. It took you guys long enough to come get it...i must have called you guys 10 times(a lie)" Meanwhile, I'm collecting $54k per day in interest on that 30 year. =D If they try to prosecute, just claim temporary insanity. No jury would convict.