The war crimes in Ukraine are among the worst of the 21st century, but they are just the latest in a history of assassinations and mass murder at the hands of Russian President Vladimir Putin. We know this, in large part, thanks to a team of online data detectives that calls itself Bellingcat. Since 2014, Bellingcat investigations have exposed Russia's undercover hit squads and tied Russian troops to atrocities. Suffice to say the Russian government denies everything you are about to see in this story. But that's exactly where Bellingcat comes in. Bellingcat's founder, Eliot Higgins, has created a method of mining online data and social media to put the lie to disinformation and unmask Vladimir Putin.