Cambridge Analytica is a good place to start. Previously:

• IT Pro: Cambridge Analytica models were exaggerated and ineffective, [UK Information Commissioner’s Office] claims
• Wall Street Journal: Mueller Doesn’t Find Trump Campaign Conspired With Russia
• Jacobin: Democrats and Mainstream Media Were the Real Kremlin Assets
• Washington Post: FEC fines DNC, Clinton for violating rules in funding Steele dossier
• Washington Post: Russian trolls on Twitter had little influence on 2016 voters
• Jacobin: It Turns Out Hillary Clinton, Not Russian Bots, Lost the 2016 Election
• Matt Taibbi: Move Over, Jayson Blair: Meet Hamilton 68, the New King of Media Fraud The Twitter Files reveal that one of the most common news sources of the Trump era was a scam, making ordinary American political conversations look like Russian spywork
• Jacobin: Why the Twitter Files Are in Fact a Big Deal On the Left, there’s been a temptation to dismiss the revelations about Twitter’s internal censorship system that have emerged from the so-called Twitter Files project. But that would be a mistake: the news is important and the details are alarming.
• MSNBC Repeats Hamilton 68 Lies 279 Times in 11 Minutes
• Matt Taibbi: CIA “Cooked The Intelligence” To Hide That Russia Favored Clinton, Not Trump In 2016
• Aaron Maté: Under Trump, the CIA is still covering up its Russiagate fraud
• Matt Taibbi: Note on New Trump-Russia Disclosures Thanks to explosive new document releases, the Russiagate hoax is now exposed, commencing a new era that will be about accountability for the guilty
• Matt Taibbi: No Doubt Left: Russiagate Was a Cover-Up
• Chris Hedges: Why Russiagate Won’t Go Away The cynical con the Democratic Party and the F.B.I. carried out to falsely portray Donald Trump as a puppet of the Kremlin worked, and continues to work, because it is what those who detest Trump want to believe.