You’ve heard a lot about the data Facebook gathers on its users. Examine what Facebook knows, and how it knows it. Subscribe on YouTube: bit.ly/1BycsJW In “What Facebook Knows about You and How,” examine the platform’s use of so-called “shadow profiles,” to the main ways Facebook tracks you on the web, even when you’re not on Facebook and more. This digital video accompanies FRONTLINE’s two-night investigation of Facebook. For more on Facebook, data, and privacy, watch The Facebook Dilemma, here: www.pbs.org/wgbh/frontline/film/facebook-dilemma/ Twitter: twitter.com/frontlinepbs Facebook: www.facebook.com/frontline Google+: plus.google.com/+frontline/posts FRONTLINE is streaming more than 200 documentaries online, for free, here: to.pbs.org/hxRvQP Funding for FRONTLINE is provided through the support of PBS viewers and by the Corporation for Public Broadcasting. Major funding for FRONTLINE is provided by the John D. and Catherine T. MacArthur Foundation and the Ford Foundation. Additional funding is provided by the Abrams Foundation, the Park Foundation, The John and Helen Glessner Family Trust, and the FRONTLINE Journalism Fund with major support from Jon and Jo Ann Hagler on behalf of the Jon L. Hagler Foundation.