Basically, these DRM block several types of equipment (CD / DVD, ...) and block or alter several software (firewall, CD burning, ...) during the game. Another very important point, the number of Installation of this game is limited to 3! If you decide to change the hardware on your PC (motherboard, graphics card, ...) or if you reformat your drive, the limit will be reached very quickly. You must then call the EA support for them to prove you're not a pirate.
In short, it could have been one of the best game of the year, unfortunately, Electronic Arts, taking its customers for thieves will kill the game.