Here are the facts:
Electronic Arts Says:
... you are limited to five authorizations. So what's an authorization? The first time you actually run the game on a machine, we will authorize that machine. If you reach the authorization limit, the game will not run on a new machine. If you make major changes to the computer (switching out multiple pieces of hardware, install a new OS, etc.) you might need to reauthorize the machine."
What they don't mention here is that a "major change" to your computer can be quite a bit less than changing out multiple pieces of hardware. In fact, changing a keyboard, mouse, or joystick or any number of USB devices could be regarded as a "major change". Upgrading drivers for you sound or video card might be a major change. The rules are not defined and you will not know for sure what may or may not use up an authorization.
So if you use up all of your Authorizations? Electronic Arts says:
"Just give us a call...
If you had a run of bad luck, some hardware failures, a botched OS install, your notebook was stolen, you spilled a coke on your keyboard - you get the idea - and all five of your authorizations have been used up, just give us a call. We'll work with you and provide as many additional authorizations as are appropriate."
What they fail to mention here is that calling Electronic Arts for technical support is not free. You will be charged 2.50/minute plus any toll charges.
Now consider the idea that you have bought 5 Electronic Arts games over time and one by one they all run out of authorizations. When the authorizations start running out, do you honestly want to call EA every time you make a hardware change to ask them to allow you to play a game you already paid for? What a hassle!
Please don't buy this game; don't support this kind of DRM scheme. I don't know if this scheme is to prevent used-game resales or if they really believe it makes a dent in piracy. It doesn't matter why, they are going too far and punishing the honest consumer, so it's time to punish their sales.