The names of the devices are as colorful as the people who used them. Monkey paw. Kickstand. Yo-yo. These are some of the cheating devices criminals brought to Nevada casinos to trick slot machines ...

The man behind me in the queue was trying to be helpful: “It’s true, though, right? They are used as weapons in Asia. I go there a lot and I’ve seen them do it—they’re lethal.” He made a sudden ...