Fuck that, COD4 used SecuROM for it's copy protection. The 200X time period will live on in my mind as the era when it became standard practice for companies to sneak some type of malware onto your PC as a 'reward' for buying their game. I was pretty careful at this time to make sure I was buying 'clean' games, but still ended up with StarForce on my machine somehow.
This annoyed me so much at the time that I completely abandoned PC gaming, and a sustained boycott of all new PC games from most large publishers is still the only way to keep your PC safe from malware.
Compared to that, always on DRM actually seems to be a step in the right direction. OK so the game might not always work (same with all DRM'd media), but at least you can delete the game from your machine if that annoys you.