I just got an e-mail regarding security clearances and social networking sites. the jist of it is that they constitute a security risk... and can and will cause you to be denied a top level security clearance. they've started asking all the students who need top level security clearances during their interviews if they have them. I coach them all to delete their pages, and to say no.
I've said this here before... but my old room mate and many of my sisters co-workers were fired from Alaska Airlines for having "objective" material on their PRIVATE myspace page. my old room mate had a pic of her and my sis standing next to a male flight attendant... all in uniform, saying "here's Jeanie and I making Will look like a Pimp" they fired her because "you can't refer to flight attendants as PIMPS"
anyways... I think I still have mine... but haven't been on them in forever. just don't really care anymore.