A guy who flew a 737 for 13 years without a license.

http://gizmodo.com/5540789/the-guy-who-flew-thousands-of-passengers-as-a-fake-pilot

Gizmodo has it,

a maintenance engineer who became a Boeing 737 pilot by flying a few nights in a flight simulator and printing a fake airliner pilot license. Amazingly enough, he flew passengers for thirteen years without any incidents.