An advertising company came up with a unique way to convey the message for a client in the security business. Link. Excerpt:
This billboard gets interactive with consumers in a very unique way -- it makes them steal. That's right: larceny. Created for client Black Tower Home Security, the billboard was debuted covered with a bunch of stuff -- mirrors, slippers, pillows and picture frames -- that were easily removed by passersby (the billboard was uniquely low to the street).
After less than 48 hours, enough people stole the stuff to reveal the message hidden underneath: "People steal."