Warnings are being posted all across Facebook suggesting that users who have received multiple friend suggestions are really infected with a computer virus. Facebook can also suggest possible friends for you to connect with. It does this by automatically examining the networks that you are a part of, mutual friends, work and education information, contacts imported using the Friend Finder, and many other factors. Facebook says you can change your privacy settings to prevent your profile from being visible to everyone as a potential friend suggestion. Facebook also says that you can tell it to remove the contacts from its suggestions system.”]
Source: https://nakedsecurity.sophos.com/2010/05/14/facebook-friends-suggestions-security-scare/