From The Guardian:
New primary source documents covering the level and depth of Cambridge Analytica data use and purported manipulation of voters began leaking on 1 January 2020.
The release of documents began on New Year’s Day on an anonymous Twitter account, @HindsightFiles, with links to material on elections in Malaysia, Kenya and Brazil. The documents were revealed to have come from Brittany Kaiser, an ex-Cambridge Analytica employee turned whistleblower, and to be the same ones subpoenaed by Robert Mueller’s investigation into Russian interference in the 2016 presidential election.
The documents are expected to continue to be released over the next few months and are claimed to demonstrate that Cambridge Analytica systematically affected voters through data and analysis, and targeted messaging.