Lock Bumping – The Technique
Lock "Bumping" is the simple way that even an amateur can open almost any pin cylinder lock.
Using a modified standard key, just about anyone can open locked doors, leaving no trace of forced entry. This is likely to become the foremost method of gaining illegal entry to domestic properties in the U.K. and Europe.
This technique, the application and the key modifications used are widely described on the internet. You can find video footage showing the practice in detail and there is a range of websites which offer for sale a range of modified keys and specialised "bumping hammers".