There's no promise that the owners of ANY social network won't give data over to the government when ordered to (or even simply asked to). Other than the whole issue of the government itself spying, facebook is actually as secure as you make it. Don't add apps. That will help control privacy. Also, you can control who sees EVERYTHING on your account other than the profile picture and "cover" image, which are always public. If you set everything to "friends" only, a non-friend can't even find your profile in a search, and can't see any information about you at all if they do find your page.
People act like facebook is such a huge security breach sharing all aspects of your life. But facebook doesn't go through your house and workplace gathering information about you... facebook can only share what YOU put on it. If you don't post bank account information, your phone number, your vacation schedule, your address, nude pictures of your wife, whatever, then there isn't going to be much to see anyway. Even the information you DO have to enter like your birthdate, gender, etc, can all be set to private where nobody but you can see it. Use it to keep in touch with family and friends, send sensitive messages as private messages like you are supposed to and put the mundane crap on your newsfeed, and there really doesn't have to be any problems.
