<http://schema.org/description>
"It is always recommended to log out of Facebook every time. It might have happened either to you or to your friend. You might have seen or heard of people leaving Facebook unattended. This may result in embarrassing comments, alteration of "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.gizbot.com/how-to/how-to-automatically-log-out-of-facebook.html>