This week at IETF, we are running a trial on MAC privacy. Fedora 20
users (like me!) are included in this trial.
Basically the concern and goal is ablitity to track a system/user by the
mac address; particularly since it is used in constructing the IPv6 address.
The trial is explained here:
https://www.ietf.org/registration/MeetingWiki/wiki/91privacy
Scroll down to see how YOU can set up your system to help improve your
privacy!