We don't see them trying to change anything on the chain with bitcoin - just trace people (and law enforcement has gotten pretty good at that to be fair). They seize wallets from people they arrest, like normal cash / assets, or get a court order to get companies holding the coin to hand them over, if the accused used a hosted wallet.

it would work exactly the same then: taking ownership of the handshake private key by which the registration means you control that name.