if you uSe FACEBOOK, your might want to READ THIS.....
http://www.guardian.co.uk/technology/2008/jan/14/facebook
Summary:
According to various sources, including the said website i have provided, YOUR information such as private messages, consumer prefrences, and variour diffrnt info that can be gaind frm the site is availble to be accessd by agencies such as the c.i.a + its friends, to gathr data intel on each individual. If your wondering why on earth they wud do such thing, it mentions it in the report.
P.s YOU are freely allowing access to wealth of info, because YOU gave CONSENT via the TERMS + CONDITIONS. If you dont agree with whats being said, read facebooks terms+conditions.