<http://schema.org/topics>
"de-friending,defriending,Facebook,linkedin,Lists,MySpace,Sex &amp; Love,Social Media,Social Network Lists,social networking,social networks,Twitter,web,web 2.0"^^<http://www.w3.org/2001/XMLSchema#string>
<http://mashable.com/2008/11/25/social-network-defriending/>