A Bic pen opened Kryptonite's 'unbreakable' $90 bike lock — a flaw known since 1992

In September 2004, Chris Brennan, a San Francisco network security consultant, posted to BikeForums that his Kryptonite U-lock could be opened with a ballpoint pen. Wired tested the claim: a brand-new Kryptonite Evolution 2000 opened in seconds with a Bic pen. The New York series carried a $3,500 theft-replacement warranty and claims of resistance to bolt cutters, saws, hammers and chisels.

The vulnerability came from the tubular cylinder lock at the heart of the Kryptolok and Evolution lines, and some New York-series locks were affected too. The method was not new: journalist John Stuart Clark had demonstrated the Bic technique in New Cyclist magazine in 1992, with follow-ups in bigger cycling magazines and a BBC consumer program. Twelve years later the flaw was still in the product.

The internet made the difference. Within days, 450-plus forum posts were calling the locks worthless, and US bike shops were pulling Kryptonite stock from their shelves. Kryptonite's first response offered no recall, just an accelerated move to disc-cylinder locks — a design its New York series had used since 2000 — and free crossbar upgrades for affected owners.