Even though any form of DRM will result in cries of agony, I find the copy protection attached to Battlefield: Bad Company 2 to be quite reasonable. You can read this official blog post on the anti-piracy measures, or watch as I attempt to cram a good chunk of juicy info into four brief paragraphs.
The .exe will be wrapped with SecuROM that only runs when the game is running. Authentication is handled one of two ways: either you have the game disc in the DVD drive, or you go online just once. If you purchase Bad Company 2 as a digital download, you of course must go with the online method.
After your game install has been authenticated via the Internet, you’ll be able to play single-player offline and online multiplayer without a DVD, even if you purchased a hard copy of the game. 10 machines can be authenticated simultaneously, with one authentication staying valid for 10,000 days.
For deauthorizing, you can either do it manually or uninstall the game. As is usually the case, if you run out of your 10 activations, EA’s tech support can give you more. My biggest concern with DRM is when it forces online connectivity at all times, so again, I think DICE’s solution is pretty manageable.
Battlefield: Bad Company 2 PC DRM Detailed [Shacknews]