> They produce evidence of tampering. That's why one of the more advanced challenges in lock picking is to minimize the amount of evidence you leave. Eg even

> They produce evidence of tampering. That's why one of the more advanced challenges in lock picking is to minimize the amount of evidence you leave. Eg even a normal pick can leave some scratches on and in the lock in different places than a normal key. If I remember right, 'bumping' is an interesting technique partially because it leaves even less of a trace.