In practice, how many housebreakers use bump keys? There are easier ways, and the person would not carry incriminating evidence on himself.
An example of this is the old style of Venner parking meter used in Britain. They used tubular keys for the cash boxes and were keyed alike over fairly wide areas. Thieves used false keys made from glass tube, so if they were caught they just dropped the tube and stood on it. It would have worked well for the 'maker' of the keys as they probably had a fairly short life. The police managed to retrieve one of these 'keys' intact.