Thomas Cane’s “Santa Claus detector,” patented in 1996, combines yuletide spirit with cold-hearted espionage. Kids booby-trap the hearth as shown on Christmas Eve, and if the decorative ribbon is pulled during the night, the stockings light up, giving proof of the fat man’s visit. “This is particularly important to young children, providing reassurance that the child’s good behavior has in fact been rewarded by Santa Claus.”
The patent abstract says that the same technology can be used to monitor the Easter Bunny and the Tooth Fairy. Presumably they’re working on countermeasures.