Word for the day: "knuckle-buster"

[A] 68-year-old Ohio businessman has stockpiled more than 8,000 of the old-fashioned credit-card-processing machines, known for their tendency to scrape the fingers of the merchants who operate them. Mr. Matthews keeps the machines boxed up individually on the shelves of his 12,000-square-foot warehouse, ready to be shipped at a moment's notice. He has enough spare parts to assemble another 2,000 if need be...

But Mr. Matthews has been ringing up a few more sales lately. He credits a series of high-profile security breaches—including an incident that prompted restaurant chain P.F. Chang's China Bistro Inc. in June to start using manual imprinters at its 200 restaurants—for easing the knuckle-buster bust, at least temporarily...

He says he recently was forced to pay cash at a bar while vacationing in Lake Tahoe because a sudden storm knocked out power and the restaurant didn't have a knuckle buster on hand. The devices are also sometimes used by merchants who don't have immediate access to an electronic system, such as a car-service driver or a seller at a street fair.

More at the Wall Street Journal.