Nothing works more in a thief's favor than people feeling secure. That's why places that are heavily alarmed and guarded can sometimes be the easiest targets. The single most important factor in security -- more than locks, alarms, sensors, or armed guards -- is attitude. A building protected by nothing more than a cheap combination lock but inhabited by people who are alert and risk-aware is much safer than one with the world's most sophisticated alarm system whose tenants assume they're living in an impregnable fortress.
Sounds like a great read - I think I'm going to pick it up for some winter break reading.