From Rap Genius, a chart showing mentions in rap songs of popular social sites and apps like Twitter and Instagram:
Compare with the graph for the same terms from Google News:
And here's the graph for general search terms. (I excluded Snapchat from the Google graphs because Google wouldn't allow 6 search terms at a time...it barely showed up in either case.) Twitter rules the rap roost, but Facebook demolishes everyone in general and news search traffic.