The ISC shares good advice on being careful with links posted in Facebook
Facebook – Be careful with potentially malicious links
QUOTE: We received an email from a reader today about a link on his wife’s Facebook wall. The link indicated that a friend had tagged her. When he tried to remove the post from her wall it would not allow removal. He reported it as spam. Apparently a friend of hers clicked on the link and got infected. The link point to a malicious site with random file names. Let this serve as a reminder to everyone not to click on links until you have checked out the source.