Quote from: posi on May 29, 2020, 09:50:28 PM

-snip- but I'm totally sure that wallet 3DykGaJ7SGtbE7jqqntB4WBKJf9pcZZbd2 belong to an exchange site.

I did a short websearch and the result suggests that you're right.

First, 3DykGaJ7SGtbE7jqqntB4WBKJf9pcZZbd2 belongs to wallet "00000014ea8b260f" according to walletexplorer;
Then, the second listed address was tagged by whalealert as "Coinbase Exchange": whale-alert.

Quote from: kryme on May 29, 2020, 06:46:23 PM

Full Disclosure: These were seized by the US Secret Service which is where the curiosity comes from.

If this was true, then it will be very hard to track since Coinbase have the control over it.
Eg. They can use other UTXO to send the funds to US SS; or spend the funds from the address in question for user withdrawals.