FILE - In this April 12, 2016, file photo, Facebook CEO Mark Zuckerberg speaks during the keynote address at the F8 Facebook Developer Conference in San Francisco. Facebook has unwittingly allowed groups backed by the Russian government to target users with ads. That's after it took months to acknowledge its outsized role in influencing the U.S. election by allowing for the spread of fake news. Now it is under siege, facing questions from lawmakers and others seeking to rein in its enormous power and demand more transparency. (AP Photo/Eric Risberg, File)