Social networking & recruiting

http://www.stuff.co.nz/4690349a28.html

Thought provoking article (link above) I thought on social networking sites being used to screen candidates. I’m a bit slow and had always seen them as a great source of candidates but had missed the screening application. Not sure I’d dismiss a candidate based on the content of their facebook site but maybe it does give a little insight into what they are all about?
22% from the careerbuilder survey reckon they have!

But how does this work if it is mostly permission based?