Useless, dangerous, once in web, forever in web!
Better think twice before register, social Web is "Highly Dangerous", used ie. by stalker, Firms (Human Resources) and so on.
This is a safe and secure site. They monitor privacy problems closely. Their customer support line is very helpful. Good way to connect to lost/old friends, and possibly make new ones.
Privacy issues has always been the on/off thing in facebook, which shouldn't be the case. Though it's useful for friends finder, it can also be annoying as the browsing time has become slower too.
There are also concerns that spams or any malware may intrude due to the lack of confidence into the facebook's privacy issue.
If you're gonna give profile information anywhere, try doing that elsewhere that has SSL and NOT at this location. With SSL, nobody can ever see this information, therefore your identity will be safe!
EDIT: Zlob trojan distributors have been confirmed to frequent this site! Be careful!