For my needs, Linux is every bit as good as XP, and I find the extensive shell scripting to be quite handy (if somewhat cumbersome) at times.
Strictly out of curiosity, why are you concerned with the DMCA if you're running Firefox on Linux, or even Windows for that matter? Read the bill some time, a majority of people that oppose it don't even do
that. Just because a bunch of congressmen want to subjugate humanity through willing misinterpretation of its provisions, that doesn't mean YOU have to play along. Know what it says, and you'll have all the information you need to defend your civil liberties.