They kept following transactions on the blockchain, but it's not clear how the private key became in the posession of the FBI.
The FBI specifically has had expanded Congressional authority for like 10 years to operate extraterritorially on cyber matters
FBI agents will show up physically in any country and request cooperation from local municipal police (maybe) to seize electronic property as well as affect arrests in a way compliant with both jurisdictions. Given that private key crypto seizure is consequence free and irrevocable, if the FBI had access to the memory at a foreign data center they could have just taken it without worrying about local procedural nuances.
Using crypto the proper way already shield against this, because you have to assume that you can't trust your own security or the data center operators, let alone the state. The server should only have the Master Public Key[1] for giving a one-time use address and rotating down the index in one of the address trees immediately after any input is received (rotate to a new account upon receipt of funds, new accounts are from an infinite tree of arrays at each node). The mnemonic for the master public key would have been generated offline and never on any device. Moving the funds, whenever one feels like it, can be signed offline and physically handed to a node that will append the signed transaction to the blockchain.
[1]Bitcoin Improvement Protocols - BIP 44 (2014), BIP 39 (2013), BIP 32 (2012)
but anyway I'm leaning towards it being a private key on Coinbase that they got a warrant to check for, and it was correct, and they seized those assets
Kinda like data scientists - they can be masters with a couple of libraries and concepts, but if you have a data science team you also are more or less guaranteed to have a jupyter notebook open to the world, or something along those lines.
Since they created the internet, they have field advantage. It's almost impossible not to use a US based provider, it goes as deep as ipv4 distribution.
Less than once if the US were, purely hypothetically, to have a well-funded foreign sigint operation that might cooperate with domestic law enforcement on priority issues.
Forgive me if this is a dumb question; I have not used a blockchain explorer for anything consequential. Isn't that wallet just the last place it ended up? So, you have chain of custody but does that prove that the owner of that wallet is the "target"?
In a way it's similar to getting stuck with counterfeit money. You didn't do anything wrong, but no one is going to just hand you the replacement real money you "deserve" - you just got unlucky.
Can anyone here (hn) add anything?
It seems like steps in the investigation, or process to identifying the bad guys were left out.