a) What people will reveal in a public forum. I'm a computer guy and understand the damage that can be done with such information.
b) The ability of such tools to link people...
1) I'm talkin' long lost people from your past.
2) to people that you didn't realize you had a connection with.
3) with incredible talents and interest unknown previously to you.
I guess we really are only Six Degrees away from Kevin Bacon. Well - maybe seven...
c) The new links that you can find
Check this one out - An article by a Facebook friend, Tom Skinner, connect to me by - what else - prep sports.
A Fallen Star.
I remember when the phrase was so innocent.