&gt;  It&#x27;s technically true that any I.P. address might be the source of malice. Yet, Tor&#x27;s I.P. addresses will <i>steadily</i> be the source of a <i>ton</i> of malice with <i>no resolution</i> of that problem.<p>Which makes blocking Tor seem attractive until you still need some defense against the attacks from arbitrary other IP addresses, and once you have those defenses you can use them against malicious Tor traffic and no longer need to block its legitimate users.<p>&gt; Good call. I saw this coming. There were already talks by Ross Anderson IIRC about how critical it was for forensics to get the port number and time-stamp since CG-NAT would make I.P.&#x27;s useless. Already is in some areas.<p>And even then it&#x27;s assuming the carrier has port-level logs to compare against. If you have ten million customers who on average make one connection every ten seconds and a connection log entry is 50 bytes then you&#x27;re writing 50MB&#x2F;sec of log entries, i.e. &gt;4TB&#x2F;day. If they keep them at all it&#x27;s not going to be for very long.<p>It seems like it would be a lot easier to move identities to some kind of proof of work based pseudonyms than to keep trying to force IP addresses to serve a role they were never designed for and the casting into of which causes no small amount of collateral damage.<p>&gt; I&#x27;m more worried about the routing tables, though, if IPv6 got massive surge of traffic. Never looked to see if they fixed early concerns about how well Tier 1-3 HW would handle it vs IPv4.<p>Part of it is that IPv6 addresses are allocated in larger blocks, which means less address space fragmentation because nobody runs out and has to come back for another non-contiguous block, which means more addresses per routing table entry. And the rest of it is that memory is cheaper than it used to be.