A study by research firm Sophos indicates that Facebook users are very willing to give personal information to complete strangers. The firm set up a fake Facebook entry and then made "friend" requests to hundreds of other Facebook users. Most of them happily revealed enough personal information (family names, photos, etc) to make it easy to steal that person's identity, according to Sophos. Among the items Facebook users were willing to share was their full date of birth, which is used by many organizations to validate identity.