Cambridge Analytica, a firm specializing in using online data to create voter personality profiles in order to target them with political messages, ran data operations for Donald Trump's presidential campaign. The company was funded by Trump supporter and hedge fund billionaire Robert Mercer, and former Trump senior adviser Stephen Bannon once sat on its board. The company, which began working for the Trump campaign in June 2016, promised that its so-called "psychographic" profiles could predict the personality and political leanings of every adult in the United States.