The San Francisco Bay Area is home to at least one-third of the value of the entire U.S. stock market. Late last year, you couldn't escape a chilling billboard campaign, meant to be cheeky, from an artificial intelligence start-up: "Stop Hiring Humans." And on Saturday, somebody tried to AstroTurf a trollish Billionaires March through the city in defense of Silicon Valley's 21st-century robber barons. Only a few dozen people showed up, heckled along the way by passers-by. The billionaires themselves also seem to be on the move. In recent months, Mark Zuckerberg, Larry Page and Sergey Brin have all purchased homes outside California, potentially bringing their hundreds of billions of dollars with them. Others have spent the past few months raging about the injustice of the state's new politics of class warfare.