Two points:

1. Depending on the interface (NIC) & driver, you can change your 
Ethernet MAC address with NetBSD any time you like.

2. This is no different than the way that IPv4 works, when used as 
originally designed. If you have a dedicated connection to the 
Internet, you typically get dedicated IP address space, and those 
addresses will be put into the DNS, and will identify you at every 
other host you communicate with.

Traffic Analysis is always a worry, no matter what communications 
medium you use. Did you know that the telephone company records the 
number for every call you make, and every call you receive? They even 
print it in your bill! Horrors!

	Erik <fair@clock.org>