<http://schema.org/url>
<http://www.businessweek.com/articles/2013-01-28/twitters-vine-has-a-porn-problem-just-like-the-rest-of-the-internet>
<http://www.bloomberg.com/bw/articles/2013-01-28/twitters-vine-has-a-porn-problem-just-like-the-rest-of-the-internet>