This is really surprising, given that the Bitfinex hack was quite complex (unless they had inside knowledge). There are several ways to hold crypto for an amount as large (hardware wallet, brain wallet, pre-signed transactions, etc...)

the file was encrypted, but the fbi hacked it after already having gained access to the account (via warrent).

Which is to say, this isn't how they actually got cought, it's just how the nail will go in the coffin (and thankfully for those impacted, some funds recovered).

FWIW, if you ever find yourself in this position of owning a large amount of stolen crypto, I believe the best way to wash it would be to "robin hood it out" to a bunch of random wallets. You just happen to own 10-20% of the wallets, but the feds now have to try and track thousands of different people over years to try and identify the true thief, and there will always be plausible deniability.

Interesting idea. But you’d only need to sample a small number of wallets to see the same person appear twice.

or buy extremely expensive tangible assets (diamonds, gold, bulk quantities of drugs). But billions of dollars worth? Forget it.

seems like the FBI was investigating for another unspecified reason, got the warrant for access to his cloud accounts, encountered encrypted files, and spent the next few months brute forcing or attacking the encrypted files until January 2022. they had marginal success with that effort but fortunately the files they got open were the jackpot with private keys and all sorts of damning things.

this is a strange one, because the IRS agent is the one that made the call.

so FBI, DOJ and IRS are involved.

The IRS agent actually suggested wire fraud and CFAA along with money laundering and defrauding the US (an IRS thing about revenue its owed), which makes sense, but DOJ has only moved on "conspiracy to commit money laundering" and "defraud the US".

This should all be taken with a big grain of salt. The official story be just parallel construction to give cover to say zero day hacks or other covert espionage etc.

Bribing or planting support agents as employees at every cryptocurrency company seems pretty easy.

They likely have proper cooperation without being public about it, like how tech companies engage with Law Enforcement.