https://www.bleepingcomputer.com/news/security/police-tricks-deadbolt-ransomware-out-of-155-decrypti...
Dutch police with Responders.NU "exploited" the time gap between the decryption key is released and the transaction is confirmed on chain. By initiating a low fee transaction at peak hours, they maximized the chance of success as well as number of key that can be recovered - since the ransomeware gang once aware of this "vulnerability" of their own scheme (within several minutes) the trick is done for.
