I've been ranting about DRM for months, that it is, by definition, a trojan horse.
As for the legalities, right now it's the wild wild west. They can say anything
they want in a EULA. It's when it gets to court that issues get defined. You can sue them.
Maybe you'll win. Maybe not. If you hack their copy protection, then they have
to sue you if they hope to get satisfaction.

The real worrisome thing is that stuff like this is only experimental, and that they
are eventually going to ask government for a final solution, mandatory
DRM designed in to all hardware and software.

http://www.eff.org/IP/DRM/