&quot;NAT isn&#x27;t providing ANY security&quot; - except for the fact that there&#x27;s no way for a host outside your NAT to initiate contact with any host inside your NAT. That sounds quite a <i>lot</i> like security. As for &quot;your private addresses are betrayed all the time by your browser&quot;, I&#x27;m not sure what an internet host is going to do after discovering my IP address is 192.168.something that they couldn&#x27;t already do.