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File photo of Facebook CEO Mark Zuckerberg holding a propeller pod of the solar-powered Aquila drone during the Facebook F8 conference in San Francisco, California

Facebook CEO Mark Zuckerberg holds a propeller pod of the solar-powered Aquila drone on stage during a keynote at the Facebook F8 conference in San Francisco, California April 12, 2016. Facebook Inc said July 21, 2016, it had completed a successful test flight of a solar-powered drone that it hopes will help it extend internet connectivity to every corner of the planet. REUTERS/Stephen Lam/File Photo

Facebook f8 developers conference

January 1, 1970

Zuckerberg introduced the Facebook "timeline" Sept. 22 in San Francisco at the company's f8 conference for some 2,000 entrepreneurs, developers and journalists.