People mining ;-)

data people mining - could be used for good or bad purposes just like everything else in life.

www.pipl.com
www.reunion.com
www.classmates.com
www.facebook.com
www.twitter.com
www.linkedin.com
www.myspace.com
www.switchboard.com
www.jigsaw.com
www.google.com
www.bing.com
www.rootsweb.com
www.tributes.com
www.legacy.com

(source)