¶ … unethical for employees to use Facebook during work hours provided that 1. It does not interfere with their work duties and 2. They are not expressly forbidden from doing so according to company policy. However, the issue is not employers exercising their legitimate rights to monitor employee posting on work computers, but what prospective employees (and existing employees, depending on the policy) say and do on their social media accounts away from work, on their home computers and mobile phones. It is not 'easy' to find out personal things, necessarily, online. Some people do attempt to enact a certain amount of screening in terms of how much is visible to the public on Facebook. Some people use privacy settings so that only close friends and relatives are privy to what they post. When employers ask for Facebook passwords they are intruding into a private sphere in which there is a legitimate expectation of privacy. Just...

Merely because it might be easier for someone to 'hack' into someone's account than to unpick a diary lock does not mean that the existence of technology gives the employer or a potential employer the right to do so.
It is true that employers are within their rights to monitor email sent on the corporate Intranet and company equipment. But employers are demanding that prospective employees turn over Facebook passwords for accounts the employees have established using their own equipment. If employers do not want employees wasting time on Facebook at work, they are within their rights to prohibit them from doing so, but that does not give them the right to monitor what employees do 'for fun'…