Direct TV has such a monopoly on the NFL right now it's not even funny.
An alternative to illegal video is radio! There's an awesome (LEGAL) site to get radio feeds from almost any market out there. http://www.thegamelive.com
Very helpful source of free online radio feeds, especially for those Thursday night games on NFL Network for those of us who are NFL Network deprived. Just turn that on and you can listen to the game straight from your computer.
P.S If this is also a copyright infringement I apologize.