text: A Facebook Inc. logo is pictured on a desktop computer's display, Milan on March 29, 2018. Facebook Inc.s co-founder and chief executive officer Mark Zuckerberg has been called to appear before a House panel as fallout continues from revelations that Cambridge Analytica had siphoned data from some 50 million Facebook users as it built a election-consulting company that boasted it could sway voters in contests all over the world. (Photo by Alberto Pezzali/NurPhoto via Getty Images