any Organization
Calling my Congress rep has done wonders in the past (was having trouble with my passport application, he got it worked out in hours after my struggling for a month), but he's already fighting the good fight on this issue, I've left him a note that he's kicking ass and to keep up the good fight.
It isn't useless, it just isn't effective in every situation, especially when your representatives are willfully ignorant of the damage they're doing. If they don't want to hear about it, and are getting inundated with the same message, they'll further cut off