We've all been there; someone puts up a CS so blatantly over-powered that it's baffling they assumed no one would call them out on it.  What's the most stupidly powerful character you've seen someone put up (without naming names, obviously)?

I'm not talking characters who are just a little too perfect -- I'm talking characters who practically break the setting.

Years ago I started an island survival rp where the characters were survivors of a plane crash.  But one guy decided he was a Jason Bourne type action hero and started trying to hand out machine guns to the other players, despite everyone telling him that that didn't fit the setting at all.  So he wrote like a page worth of description of him murdering the other players and left; it was surreal.