Some folks in my industry have been passing around this article and others like it:
Nobody ever has the right to demand your username and password to Facebook or any other social networking site for any reason. Period. Even the police.If Facebook learns that you gave your username and password to someone else so that they could log in as you, Facebook would shut down your account as it breaks the terms of service (TOS) contract you sign to be able to use Facebook. (Section 4, Item 8 here: http://www.facebook.com/legal/terms)
Never agree to give your username and password for any social network to anybody else, ever.Companies do NOT have the legal right to ask you to do so as a condition of employment and if they refuse to hire you because you refused, you probably have legal grounds for recourse; though likely there have not yet been cases elevated to a precedent setting level. If a company asks you to login to social media and asks you to allow them to use the mouse to navigate, you are breaking TOS. If they ask that you login and they be allowed to look over your shoulder as you navigate upon their direction, they are not breaking the TOS nor are you; yet they still have no legal right to demand it as a condition of employment (again no case has been tried to date of which I am aware.) One company in particular (http://www.socialintel.com/) is gathering data about job candidates for employers and many other companies are emerging to follow in their footsteps. Any institution that wants to know anything about your activities on social media can go to companies like Social Intelligence to get all they need, but even Social Intelligence can only gather data you have allowed to be made public in your account settings. Government and Law Enforcement must provide a warrant and petition Facebook to get your private data. Terms of service at sites like Facebook and Twitter are such that the user must always grant permission for any data beyond public data to be shared. When you use your Facebook creditials to login to a website or use an application or play a game on Facebook, you are prompted to give that website, game, or application permission to access your private data (IE Huffington Post, BeKnown, or Farmville) in order to play. Once you have given that permission, all bets are off and your privacy is in the hands of the website, game or application, not Facebook – so choose the applications, games, and websites you give that permission to wisely.