Note: MAC address definition (from Wikipedia): A Media Access Control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment.I am not too worried about it, because I don't currently see any way for someone to exploit this data. When I tested it, I found it pretty accurate. Try it out and see if works for you.
Bonus tip: Do you want to lookup the manufacture of a MAC address? Check out the following site (http://aruljohn.com/mac.pl), put in the MAC address and it will tell you which vendor manufactured the device.