SOME HISTORY
Cambridge Analytica, a British consulting firm owned by: Alexander Nix (CEO), Robert Mercer, Rebekah Mercer, AND Steve Bannon, used data mining techniques in an effort to meddle with the 2016 electoral process. PLEASE NOTE THAT STEVE BANNON IS A KEY PLAYER HERE.
Bannon was Trump's Chief Strategist and Senior Counselor to the President.
Cambridge Analytica started in 2013 as an offshoot of the SCL Group, partly owned by Alexander Nix. Directly from the SCL website:
"SCL Group provides data, analytics and strategy to governments and military organizations worldwide. For over 25 years, we have conducted behavioral change programs in over 60 countries & have been formally recognized for our work in defense & social change."
From Wikipedia: Laurence Levy, a lawyer with the law firm Bracewell & Giuliani, advises Rebekah Mercer, Steve Bannon, and Alexander Nix on the legality of their company.
Giuliani was Trump's supporter while he was campaigning and he is currently the president's advisor and lawyer.
What a web! Steve Bannon was part owner of Cambridge Analytica and Giuliani, the president's personal lawyer, was aware of the inner workings of the SCL Group.