Yup, my company had a clause that I could never talk bad about them in one contract. I refused to sign as I don't give away civil liberties for money. What amazed me was that almost no one else even bothered to read it before signing.
I also to opt-out of Rapiscans and get pat-downs at the airport to stand up for my 'liberties'. After feeling violated after the recent 'enhanced' one where some dude rubbed every part of my bait and tackle for 2-3 min I decided to give up that fight to. No money though.
Modern America, eh?