I don't use facebook, because I think a free-software based & decentralized social network would be the right way to do social networking, but if the rest of the people want to give away their info, fine by me.
If someone I know wants to give my info to fb, it's fine too, but he/she loses part of my trust.
I value the freedom to do whatever you want with the data you have more than the convenience of the government protecting whatever data I foolishly gave away to someone.