Rapper MC Hammer, for instance, was a big hit during his 1992 U.S. tour but bombed in Mexico City the same year.

FORBES: Rock 'n' roll en Espaol

It spread first, he says, via Twitter and influential tech celebrities like rapper MC Hammer and online personality iJustine, who changed their online avatar images to support the cause.

WSJ: New, Old Media Battle Over Net Rules

Besides a youngish crowd of Facebook employees, also in attendance were a number of Silicon Valley investors and executives, from Yelp Chief Executive Jeremy Stoppelman to angel investor Ron Conway to rapper-turned-investor MC Hammer.

FORBES: Obama And The Facebook Crowd Connect In California