I wonder what the average time the user will disconnect it after they don't get paid?
It may be worth it to just sacrifice it after a month. I am sure it is profitable, but as people become more aware, it will be harder for them to do this.
My college used to do similar. If you did not register your MAC address, you would be DHCP assigned into a walled-garden IP block.
We found we could run an IP scanner on the authorized subnet (from a computer with a whitelisted MAC), and find the unused IPs, and just set those statically for 'visitors'.
I can see its applicability in any kind of chain of trust for distribution of physical goods that have a potential to be counterfit or improperly handled/processed.
Also, I see a possibility for licensing/DRM of some types of media IP.
That does not mean it needs to be distributed, though.
Is it necessary to be based on the prefix, or can it be implemented by pattern, for instance, every even byte is zero, or the 4 bytes after the first 3 bytes must be all 7s, etc?
Is it simply brute-forcing hashes, looking for matching patterns that are not yet known?