A burglar who needed money to pay his income taxes decided to rob the safe in a store.
On the safe door, he was very pleased to find a note reading, "Please don't use dynamite. The safe is not locked. Just turn the knob."
He did so. Instantly, a heavy sandbag fell on him, the entire premises was floodlighted, and alarms started clanging.
As the police carried him out on a stretcher, he was heard moaning, "My confidence in human nature has been rudely shaken."