If someone pulls out a scam such as this one, then we can assume that he won't be stupid enough to leave some link to his identity that can be traced. The Bitcoin wallets that are used for this extortion purpose will remain inactive for many years. And even after that, the coins will be moved using a Bitcoin mixer or will be converted to altcoins or fiat using P2P platforms which doesn't require KYC information. It is still possible to trace the perpetrators, but that is going to take a lot of effort and the law enforcement authorities won't be interested unless some high profile narcotic or terrorist linkage is there.