As a fan of both Numismatics and Macs I found a recent article in 2600–The Hacker Quarterly most troubling. "A Penny For Your Laptop" (Autumn 2007 issue, page 19) by Atom Smasher demonstrates a very simple vulnerability in the Kensington Micro-Saver Notebook Lock. Apparently it can be unlocked very simply, quickly, and without destroying the lock or computer by using a coin to add tension, and spinning the dials until they stick.
The scariest part of the article comes near the end:
People are creatures of habit, and in most cases the four digit combination used on the lock will probably be the same PIN as the owner's bank card, voice mail, luggage locks, etc. In many situations just learning the PIN may be more valuable than the laptop.
Um, how many of us are guilty of that one?
I used to use Kensington Micro-Saver locks frequently (mostly at trade shows where I was exhibiting) but haven't used one in quite a while. I'd be interested in hearing from you if you've tried it, or if you have a link to a video showing it in action.
The article is clearly written, informative, and he even suggests a solution to the problem. You'll have to trudge on over to Borders to get a copy of the latest issue of 2600 though, it's not available online.
Update: YouTube videos are available showing a MicroSaver lock being opened with a piece of paper, and an empty toilet paper roll. Kind of reminds me of that hack to open a Kryponite bike lock with a Bic pen.