Safecracker has never really been a viable profession, but a century ago, “yegg” or “yegg-man” was the name for that job. This slang term for a burglar (specifically of safes) was popular in the early 1900s and was associated with the train-hopping culture around the Great Depression. The word “yegg” can be traced back to the 1900 American Bankers’ Association convention, at which a series of bank thefts were discussed. The Pinkerton Detective Agency had apparently hounded the thief so perniciously that the stolen funds were returned, with a letter signed “John Yegg.” “Yegg” was found to be a pseudonym (the real thief’s name was William Barrett), but the word stuck as slang for a safecracker.