<http://schema.org/topics>
"Apps and Software,dreamer,Facebook,hackathon,immigration reform,linkedin,mark zuckerberg,Politics,Reid Hoffman,Silicon Valley,Uncategorized,U.S.,World"^^<http://www.w3.org/2001/XMLSchema#string>
<http://mashable.com/2013/11/22/hackathon-for-immigration-reform/>