You must watch this Ad Age video. It touches on Gen Y, the first demographic group to totally grow up in a digital world and the position this places marketers in regarding how much personal data we can safely use.
Very relevant given the latest FTC ruling regarding regulatory principals for behavioral advertising.
There are also a few funny moments on the video, like when Emily Riley of Forrester Research talks about Gen Y posting themselves doing things illegal things on Facebook and then how they go looking for a job.
All I can say is...the use and type of data available for the average consumer is changing and changing quickly.
Hope you enjoy to video.