Lets take a look at SOPA / PIPA. Because enough people actually contacted their senators and got media attention, legislators thought twice about their stance.
The real question is would FB alone be enough to get people to act and get the media coverage they need to influence the legislators? IMO it's doubtful unless something dramatic happened like a service interruption...
if ever there was a post that deserved a 6, this is it.
Don't be such a glory hog, I personally like the one above yours that says
And my great-grandfather wouldn't have it any other way.