This topic has been mentioned on a few occasions but has not been heavily addressed since technology is changing at such a fast pace that the legal system has barely been able to keep up. But this ebook put out by PeopleClick just this week really does a great job of summing up what typically may seem like common sense to some but could easily get someone in a law suit if they aren't careful.
So I encourage all of you to check out this ebook on Employment Law as it relates to Social Networking. It has some really great points that we should all be sure to remember as we continue to use social networks, like Linkedin and Facebook, as a major source for recruiting.
Link to ebook: http://www.peopleclick.com/resources/wpaper/Social_Networks_Employment_Law_eBook.pdf