I post on Twitter once in a while. Was on the other day posting some links and Obama’s Florida campaign ‘followed’ me. I immediately blocked them. Two can play that game.
They followed me, too. I don't block them, I let them get my Tweets full-strength without acknowledging them. THEN they unfollow me or even better, they block me. Just because they follow you doesn't mean they will be able to post to you or that you have to follow them.