Quick anti padlock trick

[Steve]

Cheap padlocks, the type that lock automatically when you close them rather than you locking them manually by turning the key, can often be opened by hitting each side simultaneously with a small hammer. The shock pushes the locking catch out of the notch and the lock springs open. Exposed padlocks without high shoulders can be simply twisted off with a large adjustable spanner, the same trick on a decent padlock often breaks the ironwork off the door.

I had a workshop in Bermondsey, so I've seen these a few times.