Social Security is key to driver's license, school records, banking and passports. And these are things that help people to pose as you, or to sell your information to someone who will.
And something as simple as your birth date, when used in conjunction with your Social Security number, can unlock the door for identity theft.
1. Your Profile Picture
Your picture shouldn't have any clues about where you live or work. If you're standing on your street and you can see the house numbers, that gives a clue about your address. If you're posing wearing a job uniform and it says the name of the restaurant where you work, that gives them more information.
Internet quizzes are becoming more popular. There are intelligence and personality tests that look like fun and might ask you personal questions such as "how much did you drink last weekend?" That information is public, out there and could be sold to marketers.
3. Friend Requests
Facebook suggests that you don't accept friend requests from people you don't know. And don't feel bad if you choose to ignore them. Also, you can enable privacy settings that allow you to customize what information you share and with whom. By customizing the settings on the privacy page, you can control who views your information, dictate who can find you in searches, as well as see your profile and photos, among other things.
4. Phone Number
Don't post your telephone number. If it's a listed number, someone could easily do a reverse lookup to get your address.
5. Status Update
Don't list if you are going out of town. If someone has your address (see No. 4 above) and knows you're out of town, you could come home to find yourself robbed.
And on a less serious note, remember that anyone can go on Facebook, including the police, your professors and your boss. So if you call in sick and then post pictures of yourself out partying later that night, well, you have no one to blame but yourself.