WebSchemas/socialAccount2
http://schema.org would be a property, expecting a URL as value and defined by the types http://schema.org/Person and http://schema.org/Organization to capture their social accounts
Markup example
<div itemscope itemtype="http://schema.org/Person">
<link itemprop="socialAccount" href="https://plus.google.com/109412257237333861202?rel=author"/>
<link itemprop="socialAccount" href="http://www.twitter.com/johndoe"/>
...
</div>