> in countries where IP address = person that rents it.
Does that actually exist today? At least IPv4 addresses I would expect to increasingly mean nothing, as address exhaustion drives more people behind CGNAT.
Even with dynamic IPs (Not NAT in this case) it's not a problem as ISPs in most countries have to keep a record who used the IP at which point in time.
CGNAT means multiple people are using each IP address at every point in time. To disambiguate customers the ISP would need to log every connection, which is a huge amount of data to keep track of and only useful if you have not only the IP addresses and timestamps but also the peers' port numbers.
I know people complain (fairly!) about comcast a lot, but some things they've consistently gotten right are stable IPs even if you don't pay for an explicit static address, and pushing v6 VERY hard.
Does that actually exist today? At least IPv4 addresses I would expect to increasingly mean nothing, as address exhaustion drives more people behind CGNAT.