How many disgruntled ex-employees does it take to rob the Louvre? Apparently just one. On Aug. 21, 1911, former workman Vincenzo Peruggia waltzed into the museum and stole the Mona Lisa, then valued at $1 million, by ripping it from the wall while no one was looking, stuffing it under his shirt and waltzing right back out. Two years later, police captured Peruggia and recovered the painting thanks to an honest art dealer in Florence who reported Peruggia to the police after he unsuccessfully tried to pawn it. Even so, the Mona Lisa exhibit remained popular during its disappearance; thousands of museum visitors lined up to see the empty space where it would have been hanging. Today the painting has a high-security room all to itself.