“We have their data – and therefore we have your data. Transactions, registration data, IP addresses.”
The 47 exchanges sold one product: no Know Your Customer checks and a promise that nothing was logged. The BKA took the development, production and backup servers, so the logs existed all along. No arrests yet, and the BKA admits many of the criminals live in countries that protect them. The users who paid for anonymity are now a spreadsheet at the BKA.