can i still be president?

When I am away from the class and signing in and commenting on all these sites, I start to get nervous. This digital footprint that I am creating.....is it here forever or can I make it go away? Some day when I am a technological expert and earning millions because of my expertise (ha), will these comments come back to haunt me? Will I end up being quoted from someone who found some of my inane jabber and then blocked from advancement in some unknown area of my future life. I have certainly tried to impart that message to my children regarding facebook, and I wonder if some of these casual comments could somehow be dangerous.