[ConservativeMind]

There are ways to change the MAC address that your PC shows the world.

Here are a few brief references:

http://www.tech-faq.com/change-mac-address.shtml

http://www.nthelp.com/NT6/change_mac_w2k.htm

[beezdotcom]

There are ways to change the MAC address that your PC shows the world.

Yes, there are many way to do this. My point is that most people don't show their MAC address to "the world" (or even a valid IP), they show it to their router. When they touch various network sites, they are likely to only be showing the MAC and IP address of their router.

Sure, some pieces of software that you run may also capture your local MAC address, and report it to a remote server (licensing software, for instance). However, I find it amusing how most people are ever so careful to change their MAC address at home, but anybody tracing IP traffic is still going to tie everything back to the router sitting right next to the PC. (Movie downloaders, beware!)