> "The DOJ said it was able to seize the funds after an FBI search warrant of one of Lichtenstein's cloud storage accounts found a file containing cryptocurrency addresses and their corresponding private key that granted access to funds stored within."
That makes sense, and of course storing them in cloud storage was a bad idea. However they could have only obtained the warrant /after/ they pretty much knew Lichtenstein was the culprit.
How did they determine Lichtenstein was the person who had the bitcoins?
How did the FBI know, hey he's the guy, lets get a warrant