"Sir we're getting all these calls about this sopa thing. They're automatic but there's a lot of them and they're all different. Its starting to tie up our phones."
...is a hell of a lot better than "no mention at all about that entertainment lobbyist's bill I rubber-stamped and then never heard anything about. Must not have been important."
Maybe...except people in congress have private lines which they use to communicate to the people they need/want to talk to. The public lines are only used for constituent and other public calls. So really what you'd be doing is blocking their constituents from calling them.
So the congressperson isn't losing any calls they needed to take and the only person being punished is their secretary. In the worse case scenario that congressperson could have a bunch of constituents who object to SOPA and you'd be blocking those calls with your own (which the congressman couldn't care less about if you aren't in their district)
That sounds great for the telemarketing and political system, to me! I tire of calls about my political stances on random issues... as well as telemarketing calls.
I believe many of these staffers keep tallies of calls and their topics, so it could still have some impact. Making the calls unique is definitely a good way to keep them from being ignored.
...is a hell of a lot better than "no mention at all about that entertainment lobbyist's bill I rubber-stamped and then never heard anything about. Must not have been important."