Next time you walk by a locked up bike ask yourself, is there a place to plug in a power tool, would I sit there and saw away at that bike? You see most thefts are thefts of opportunity. If a bike is locked up with 2 locks, if it is locked up properly then in most cases a thief will not even attempt to steal the bike. Some bikes just scream, "I am far too much trouble." Fact, locks do discourage as well as protect. They discourage by increasing the risk of a thief being caught as well as the effort, power and skill he will need to break the lock- they protect in that most thieves will never be able to break good locks no matter how hard they try.
Respectfully
Jack