If you are advising someone who is applying for a job or an employer who is selecting among applicants, Robert Sprague's article Rethinking Information Privacy in an Age of Online Transparency, 25 Hofstra Lab. & Emp. L.J. 395 (2008) may be of interest.  Sprague provides an overview of the law relating to employer's use of information available on the Internet to select employees. 

His thesis is that privacy has been defined too narrowly to encompass only secret information or conduct.  He comments that "[n]ew forms of communication allow others to view what are intended to be at least somewhat private conversations.  Protecting these conversations requires an attitudinal shift towards acceptance of the idea that just because a few people have access to information does not mean it is no longer private." 

He proposes reforming applicable laws to "prohibit employers from using publicly-available personal information that could be obtained through an Internet search in their hiring decisions."  Alternatively, he recommends passing statutes that would requires employers to inform an applicant before obtaining information from the Internet, to inform the applicant if such information about the applicant was used in deciding not to hire the applicant, and to provide the applicant a copy of the information used.