Remember the show 'Candid Camera'? Well here's a sweet little anecdote combining the 'not too bright' crook perspective as well as reversing the situation.
While setting up for a "Candid Camera" segment in a bank one day, Allan Funt (the show's host) was astonished to find himself in the middle of an actual robbery. As Funt looked on dumbfounded, the staff - naturally assuming that the robbery was a practice run of a practical joke - began clapping. So astonished was the robber that he actually dropped his gun and raced out of the bank!