File this one under security risk. If you share your address and phone number on a social networking site, you open yourself up to threats of identity theft and other personal dangers like burglaries. If you post that you're going on vacation and you have your address posted, then everyone knows you have an empty house. Identity thieves could pay a visit to your mailbox and open up a credit card in your name. Burglars could rid your home of anything of value. Even just posting your phone number gives people with Internet savvy easy access to your address. Reverse lookup services can supply anyone with your home address if you can provide the phone number.