(update: Here's another treatment of the same topic from boing boing.)
I was asked about a site called spokeo.com the other day: apparently it poses as an online white pages on steroids.
What it really seems to be is a spam engine.
The basic idea is that they go out and scrape websites for any public information with a name attached, and then let everyone on the web search all that stuff to find their friends or acquaintances. There's nothing there that wasn't already made public by someone - whether it's the person in question or not. Any notes or tagged pictures that are there for everyone on facebook (or myspace or linkedin or whatever) can be scraped by these guys - regardless of who tagged you in them.
Not to worry, though. There's a privacy link at the bottom of the page where you can request that they not make those things about you public. Of course, in order to do so, you have to give them your email address. Oh, and they'd really prefer it if you'd give them your email and password as well, just because it makes it more secure (?!) that way. No one will have access to it - not even spokeo employees! (So, what's it for again?)
Hmm. So, I go into their system and find my data.
Then I tell them the email address that goes with that data.
Then I'm sure that no extraneous, unsolicited emails will appear in my inbox, right?
Oh, and they want me to pay them a monthly membership fee in order to see all this great data.
The regular journalists I noticed said they had no real luck in getting stuff get turned non-public, and that the data on them tended to be both incomplete and inaccurate.
Sounds like a moderately elaborate way of gathering probably real email addresses along with a bunch of data to flesh out the recipients.
I recommend that you stay away.