Drones Over U.S. Get OK by Congress
I recommend you find a list of all the legislators that voted for this bill and think about voting them out when they come up for re-election.
Being that the bill passed, I suggest you start gathering supporters, and creating petitions to sign to get a repeal. You can interestingly exploit a loophole -- you can't write legislators out of state, but you can call them by phone.
Find any legislators that opposed this bill; any that are anti-surveillance or libertarian possibly. Contact people who live in their state if you can that support your views and use them to further bolster your efforts.
Normally I joke when I post this, but I'm really seriously asking you to read my signature down below and be sure you understand what I mean by it...