It gets absurd. "Owning bitcoin" is just linguistic sugar for having knowledge of a private key that corresponds to a public key that hashes to a bitcoin address that holds bitcoin. It's just a 256-bit number. In essense, every single private key represented on the blockchain becomes an illegal number (https://en.wikipedia.org/wiki/Illegal_number), and not just illegal to publish, but illegal to store and even illegal to think about (aka know about).