People have locks on their doors to keep honest people from robbing them. It does not stop professional thieves from robbing them. Honest people who see a bicycle unlock would rob it under certain conditions so it is to keep honest people honest. Real thieves my night rob the bike because there is no fun to stealing something easy to steal.

I go to the Giglio feast one year. I want to buy a shirt while I am there. They told me their are no more for sale. The rest were for those who ordered them in advance. There in a locked truck parked out in the open. I go to the truck that is locked and break into it and take a shirt and leave 20 dollars to pay for it.