May 18, 2012 7:56 am Mark Zuckerberg is pictured on a billboard in New York as Facebook goes public. Mark Zuckerberg is pictured on a billboard in New York as Facebook goes public on Friday morning. US & World Videos 2:59 2 San Jose police officers shot, injured in gunbattle at hotel 1:46 Pursuit standoff causes traffic backup in Solano County 3:23 UC Davis finds brain sizes are growing 3:36 Waymo expands driverless taxi service 5:21 A closer look: 2 police officers shot, injured in San Jose