Recently, the media has given a great deal of attention to "lock bumping", a procedure that allows criminals to open many common door locks by simply inserting a specially modified key and tapping its end with a mallet or other tool. Along with the media reports, a number of warnings about lock bumping have been circulating via email and online.

The reports and warnings about lock bumping are genuine. Lock bumping, also known as "bump keying" and "key bumping" describes a technique in which an ordinary key can be filed so that, when it is inserted into a door lock and tapped, the internal pins can be jarred in such a way that the lock will open. The majority of pin-tumbler locks currently in use are vulnerable to lock bumping, including those normally found on people's front doors. The technique is simple enough that, with the right knowledge, and a little practice, just about anybody could use it.

Unfortunately, the necessary knowledge is quite freely available on the Internet. There are a large number of easily accessible videos and tutorials that explain in exacting detail how to perform the technique. In fact, there are even sets of bump keys and lock bumping kits available for purchase.