There was a very succesful group of crossroaders in the 60s-70s who would make the rounds of all the casinos, stealing dice from the tables. They'd send these off to a place in NJ to have matching "tops" made. Then they'd make the rounds of all the same casinos, switching the tops into the game for a few rolls, and then back out before anyone noticed. Takes a lot more nerve than I would ever have!