FILE - In this April 11, 2018, file photo, Facebook CEO Mark Zuckerberg testifies before a House Energy and Commerce hearing on Capitol Hill in Washington about the use of Facebook data to target American voters in the 2016 election and data privacy. Attorney General William Barr wants Facebook to give law enforcement a way to read encrypted messages sent by users, re-igniting tensions between tech companies and law enforcement. (AP Photo/Andrew Harnik, File)