If a thief wants it, the thief gets it. If you think they are not brazen enough to work on a lock for ten minutes you are mistaken. Scenario: A van loaded with electrician tools. Parked on a lunch time (100's of people sitting at tables outside) crowded downtown Pittsburgh street. Return 20 minutes later to find van empty, while alarm was going off. Moral of the story: Most people just don't care, as long as it doesn't effect them. Guess what? Nobody saw anything either, out of convenience.