Disk locks are very popular for different security applications, including bike locks. Kryptonite faced serious legal and security issues in 2003 because the locks could be impressioned in seconds with a ball point pen. As a result, manufacturers moved away from pin tumbler locks in favor of disk locks, first invented by Abloy in 1907. Abloy is the largest lock manufacturer in Finland and produces high security cylinders that use rotating disks.
Some of the less expensive locks have poor tolerances and fewer disks. They can be impressioned rapidly with several techniques. Two of them are shown in the video. One is by John Falls with his foil impressioning system. The other is demonstrated by Marc Tobias. Watch the video.