I can't speak for everyone but from where I was raised, I have been taught that if you're hired to do a certain job, you do that job best you can without compromising the company's name. A person is being paid for a job to do, not make a mockery of things. If this means being a mindless drone during work time, then so be it, you leave your feelings outside the company door.
Then after work/contract you can basically do whatever you want. Hey if you want to run around naked in Times Square or hand out religious pamphlet, so be it, more power to you man.
Full disclosure: I used to belong to a religious group that ones in a while I volunteer to stand at malls and give out pamphlets. At work, they know this and yet I don't talk about it. I respect their religion and they respect mine. After work, we sometimes go out and have some beers and complain about the lazy supervisor