Bolt cutters: Because so many bicycle thefts go unreported, it is difficult to collect accurate data on exactly how many bicycle thefts are committed each year, and especially to know the ways in which all those thefts are carried out. From my experience working in shops over the years, though, I’ve heard hundreds of stories of stolen bikes and seen many cut locks, and most of them (not including snipped cable locks) have been cut with bolt cutters. Bolt cutters can be quite small, usually 18 to 24 inches long. They’re quick to cut through a lock, cheap, portable, and easy to conceal. They don’t work on every lock, but for the ones they do work on, it’s only a quick snip and a free bike. Once thieves know which locks they can cut with the cutters they are carrying, it is again just a matter of walking the streets looking for a target lock and bike.