I don't know what's normal now but a long time ago, 1997, I moved with a complex with 300 garages each with a remote. I opened the remote to change the battery and noticed only 8 switches for the code. 256 codes, 300 garages, drove around the complex opened 2 other garages. Even at 12 bits with 300 garages the odds are very high of a match

http://en.wikipedia.org/wiki/Birthday_problem

Weird. I did something very similar in the same year.

While locks don't keep skilled criminals out, you'd be shocked how many unskilled ones there are. Meth/crackheads routinely go around twisting doorknobs in apartment complexes or pulling on car handles just hoping to find something unlocked so they can steal whatever is there. They (usually) don't break and enter, but if they happen upon an unlocked door they'll walk in and steal anything.

Not that this is a common attack, but to add to the stew - I knew a guy who left his leather jacket in his car, which was a soft-top convertable. The jacket thief simply sliced open the top and took the jacket.

These days I just tell people to consider the inside of their car a public place, and never to leave anything in there that you wouldn't leave lying on your front fence or similar. There are simply too many ways for people to get into cars to win that game, and ultimately, few things will stop a thief who's willing to damage the car (hammer through a window, or knife through a soft-top, for example).

A car is like a glass vault on wheels. That's at least two weaknesses right there.

Most (?) robberies are not sophisticated attacks but are simply crimes of opportunity.

That's not exactly like computer security. With computer security you plan for the worst, not the average. That's why even a skilled hacker/coder can't break into banks or major websites on a daily basis.

A bank is not equivalent to your home. You may note that banks generally lock up their physical money behind very sophisticated security systems (relative to other homes/businesses). They deal with a different level of threat, and respond accordingly. Even then, they don't try to safeguard against someone physically demolishing the building, because there's only so much they can do, and at the point someone is willing to go that far, the chance they will complete the theft without being noticed and tracked is virtually non-existent.

Exactly. Lots of people don't realize that most of their door locks are there to keep "normal" people out, because dedicated criminals are typically going to find a way in.

Locks keep honest people honest.

Locks reduce the instances where dishonest people can exercise dishonestly without repercussions. But that's what much of life is about, reducing the occurrences of negative outcomes. Elimination often isn't possible or feasible.

This is a much more accurate than the old "Locks keep honest people honest" saying.

If you consider yourself an honest person, ask yourself how many times you've tried to open doors to random houses as you walk down the street. If you found it unlocked, do you rob the place?

If you need a lock to keep you honest, you may want to reevaluate your values.

The phrase is rooted in a very old memeplex, the part where religious morality and sociopathy overlap. Most ideas revolving around the concept of "putting the fear of God into someone" aren't actually for regular people with empathy. They're for sociopaths. It seems that sociopaths used to be seen as just completely normal people, undifferentiable from everyone else—and much of "morality" is actually an attempt to create extrinsic incentive systems to replace the thing that sociopaths lack, so they can seemingly function normally.

That's all to say, by analogy: locks are to keep honest-acting sociopathic opportunists honest-acting.

Right, you're exactly right, but you also seem to know a bit about sociopaths, and so it surprises me that you are implying that we don't see sociopaths as normal people these days. I've had very personal run-ins with real, genuine sociopaths in my life, and most people just have no idea that there are these people just totally walking around being treated like normal human beings. Sociopaths are not human beings, I say, because what is humanity but our empathy? And sociopaths do not have it, ergo...

...and dishonest people untempted.