The recent case of an Italian tourist who was kidnapped in New York City and tortured by people allegedly after his cryptocurrency is drawing attention to a rash of crimes dubbed “wrench attacks,” which combine cybertheft with old-fashioned thuggery. 

The term stems from an XKCD comic that depicts a “crypto nerd’s imagination” of the tech know-how that would be required to break into their digital wallet. In reality, the comic notes, all it would take is a heavy $5 wrench to threaten the crypto owner until they revealed their account password.

Such attacks have picked up in recent months, partly because stealing a digital wallet can be easier than stealing money from a traditional bank account, said Ari Redbord, global head of…