Brute Force Safecracking

If you wanted to get into a safe, but didn't know the combination, how would you crack it? The dumbest, but guarenteed to work, solution is to try every combination until one works. A human safecracker would get tired within a few hours of doing this, so Hack A Day reports someone automating this...with robots. The robot works faster than a human safecracker too.
The robot is a metal-and-plastic manipulator machine controlled by an embedded computer, and would fit in a backpack. If the thief is sneaky, and does this at a time when most people are asleep, and muffles the whirring noise made by the servos, he could sneak it into a bank at 2am in a backpack, muffle all noise in the area, let it grind away for 3 hours, grab the safe contents, grab the machine, and be gone by 6am. If he's stealthy enough, no one would even notice.
In some ways, I suppose this was inevitable. Cryptographic brute force is the only known way to solve NP based problems, and the only P based way to crack a safe would be to somehow figure out some pattern to the combination based on the manufacturer's serial number.

Security

XKCD is an online comic about math, science, and nerd issues in general, that, this previous monday, made an interesting commentary on security in general.

In the strip, he compares what most cryptology fans assume would happen with strong encryption, that their secrets are safe because it is mathematically difficult to retrieve the information, verses the actual ugly truth.

Anyone willing to spend a million dollars to decode the contents of your hard drive by force is also willing to savagely beat you with a rubber hose, (or in Mr. Monroe's strip, a $5 wrench) until you reveal the password needed to access the information. For you see, all security has some point of failure. By installing this extensive cryptography system, the point of failure has been moved from the seizing of the hard drive, to the unfortunate sensitive flesh of the owner.

Let us say that I have an irrational (or even justified) fear of home invasion, so I spend a million dollars hardening my door. My front door is now able to endure blasts of dynamite without structural damage, is essentially impossible to pick, and repels abrupt force. Let us also say that you wish to break in and steal something of mine. Maybe my stereo happens to be more awesome than yours and you want it. Maybe I have state secrets that you wish to give to a rival state. Maybe you want to arrest me because I've committed a crime. It doesn't matter why you want in, how will you do it?

Probably, you'll either bust down a side or back door, or break one of my windows and hop through it. I didn't think to reinforce those, so you make it in easily. And then my awesome stereo / state secrets / stack of money / body/ whatever it is that you wanted is yours to grab.

Perhaps you think that it is pessimistic to assert that perfect security is impossible. It doesn't need to be, though. I don't need to make my front door impossible to pick if my neighbors tend to call the police if they see someone strange fiddling at my door for more than five minutes. The safe I keep my money in need only hold off any safe cracker until I can show up with a weapon to threaten him for trying to steal from me. And if I ever need a bulletproof car, it need not resist an infinite barrage, merely keep me un-shot enough to get to the airport and get the hell out of that city.

Security is about making your point of failure impractical, not impossible. A burglar will prefer to rob that other house up the street, the one that the door never closes properly and the neighbors all hate him for blaring music at 4am. Don't be that guy and your things are reasonably safe.