This war-dialing safe-cracker opens combination safes

On most safes, you randomize the dial by spinning it a few revolutions, then dial the 3 (or 4) digits, then turn the opposite direction until the latch falls. Then you turn another 1/4 turn to retract the bolts, or turn a separate lever to open the door.

The problem with a war dialing is you need a database of the different configurations of the locks.