Comment 41 for bug 176125

I frankly couldn't care less if someone knows my MAC address. The MAC address of the laptop I'm typing on right now is 00:1e:c2:c0:52:e3. What does that get you? Not much.

If you're concerned about being tracked across the Internet, your IP address is probably the least of your concerns. Have you read the articles about browser fingerprinting? Even if you disable cookies and don't install Flash, you can still be identified pretty well. I find that much more concerning that someone knowing if I'm on Wifi or wired Ethernet, and the manufacturer of my NIC. Privacy addresses provide no protection against tracking cookies or other spyware.

Privacy addresses don't deliver much security (or privacy, frankly), and they make life much harder for enterprise admins. There's a significant difference between chasing down a few power users who enable privacy addresses -vs- having to reconfigure every machine (often manually).