As the owner of older rights in the name someone registered and/or uses as ENS address, how can I find out whom to address for my claims?

Due to the anonymous and decentralized nature of blockchain and the ENS domain service is also just a smart contract at the end of the day, it is very difficult to find out the identity behind a wallet address. There have been cases where judgements have been served to wallets as NFTs, but while that sounds cool and innovative, it does not really mean that you know whom to address in that case either. If the person is not responsive, it remains problematic.