This is kind of awesome:

That was the MO of one Willie Sutton, a celebrated American bank robber known as “the Actor” and “Slick Willie” because of his proclivity for disguises. He frequently posed as a Western Union messenger and arrived at a target bank or store just as it was opening. Other favorite getups included a maintenance man, a policeman, a diplomat and a window cleaner. Once, in 1947, Sutton escaped the Philadelphia County Prison in Homesburg, Pa., in the guise of a prison guard. When searchlights caught him trying to scale the prison wall, he yelled, “It’s OK,” which fooled the real guards and allowed Sutton to escape.