This information is boring and useless on its own, but link it all together and you could map out a whole society on your desk.
What if Mr Facebook gets a call from the FBI ordering him to relinquish information for the 'greater good'? What if your mortgage/insurance company gets access to see who your friends are and what kind of lifestyle you lead? What if someone hacks in and steals the information? Would your boss be interested to know what you do in your spare time? At the very least expect to be bombarded with e-mails which 'may be of interest'.
The more I type the deeper this could go. Better stop now and watch the snooker on TV instead.