I have a question, how can I communicate with a hacker if I only know their wallet address? In this incident, due to the significant losses, the media is reporting on it, and the hacker is certainly aware of the communication content. However, if there isn't such a big impact and I still want to communicate with the hacker, can I send messages through the wallet address?

A whale/institution that lost 50 million USDT to phishing has sent a message to the phisher: stating that if the 50 million USDT can be returned, they are willing to offer 1 million dollars as a white hat bounty.

As of now, the phisher has not responded to the message.
However, it is highly likely that they will not return the money, as it has long been exchanged for ETH and washed away through Tornado.