As part of an ongoing investigation that involves German authorities, an unnamed forensic IT company from Munich, and the FBI. Roughly 50,000 bitcoins were seized from two people suspected of money laundering and more. The two individuals allegedly got these funds while in charge of an illegal file-sharing platform.https://www.notebookcheck.net/German-police-breaks-previous-record-with-2-1-billion-Bitcoin-seizure.799070.0.html
the plural of bitcoin is bitcoin
The plural is often used when talking about a certain amount. Take a look at this CNET article, for example - https://www.cnet.com/personal-finance/investing/crypto/what-is-bitcoin/ or this one from Wikipedia where the plural is mentioned multiple times - https://en.wikipedia.org/wiki/Bitcoin
Seizure. Seizure. Seizure.