Do you like DRM? Isn't that a perfect thing to make sure you are properly licensed with all your music, movies and, of course, software? Well, folks like the EFF have strongly opposed DRM right from the beginning. One of their arguments always has been that, if thought to the end, would revoke the user the ability to work do with his machine what he wants do.
Now we see a perfect sample. Grave Rose just posted a nice link on twitter: "Gears of War DRM screwup makes PC version unplayable". It's all about a DRM cert that seems to have expired with the end result that the game no longer works. Thankfully, as we do not (yet) have the full trusted computing platform in place. So, you still change you PC. This enabled users to set back their system clocks and so the game worked again. rofl...
Granted, this is not a real DRM issue. Such an expiration date can be encoded in software ever since. With a good debugger, it is not too hard to remove it (of course, that's not legal and with DRM it is considerably more work to do...). But if we are forced to use more and more DRM and if we are forced to use hardware platforms that deny true admin access to its owner and we have legislation that outlaws helping yourself - won't those issues become the norm.
For most of the time, you could rest assured that once you had installed something, and did not change it, it was likely to run for eternity (well... somewhat). This seems no longer to hold true. The only true solution is to use as much open source as possible and say no to any DRM-enabled products.
As an interesting side-note, I am not sure if the poor gamers who set back their system clocks are in legal troubles: didn't they try to circumvent a technical copy protection? Not sure about the DMCA, but in Germany you could argue that this is an illegal attack... Happy gaming!