[jgalt212]

> For the billionth time, NAT does not provide any security as it only does address conversion. The other fields in the IP and TCP headers (such as the connect(2) side's port number, the TCP timestamp[1], badly implemented initial sequence numbers[2], and anything else that is useful for OS fingerprinting) can be used to distinguish between users[3] that share a single NATed IP address.

The above are all good points. However, using IPv6 for tracking is trivial. Getting behind the NAT is not. It should not be trivial to track. From a behavioral economics framework, the more steps a bad actor has to take to be "bad", the less less he's to do so. Conversely, the easier it easier for people to behave good, the more likely they will do so.

[mentat]

You don't have to "get behind the NAT" to track these things. Also browser plugin versions are worth a bunch of entropy.