Because a lock can mean the legal distinction between "breaking and entering" and mere trespassing.
A lock is significant discouragement to thieves as it slows access and breaking the lock or window announces their intrusion both from sound and is instantly apparent once anyone arrives at the crime scene.
Like say you have a house near a road and you have your mobile or laptop on a table, a desperate drug addict walks by, needing money for a fix and sees your valuables through a window. They will test the door and if unlocked simply walk in, drab the valuables than walk out. You could have just have popped out for a minute or be in another room, your items would simply be missing and it would take a while to confirm a theft, especially to the police who'd like think you're just an idiot who lost your mobile down the back of a sofa.
Sure, a big burly bruiser could smash a window or kick your door in, but it is a noisy and uncertain proposition. Crims want easy pickings, just grab it and go, they REALLY don't want to get caught in the act.
Also lol at Michael Moore's "Canadians don't lock their doors" he tested the doors of houses where PEOPLE WERE ACTUALLY INSIDE AT THE TIME! No locks their door when inside and awake. Better comparison would be how many doors unlocked late at night or when they leave to the shops.
Keepitclean said:
Actually, there was a campaign by the WA Police recently called "Burglar Beware" and one of the main security tips it gave to home owners was to lock their doors and windows because that is how must robbers get in.
must... resist... O... Rly...