This is from the Creative Commons FAQ:

A Creative Commons license is based on copyright. So they apply to all works that are protected by copyright law. The kinds of works that are protected by copyright law are books, websites, blogs, photographs, films, videos, songs and other audio & visual recordings, for example. Software programs are also protected by copyright but, as explained below, we do not recommend that you apply a Creative Commons license to software code.

[...] You should understand about Creative Commons licenses that they are all non-exclusive. This means that you can permit the general public to use your work under a Creative Commons license and then enter into a separate and different non-exclusive license with someone else, for example, in exchange for money. 

Zune at its first steps cannot tell the difference between a purchased track and any other when sending files through Wifi. But treating all of them the same way is a non-solution. Many have said that Zune's WiFi restriction violates the CC licenses. This is not true in legal terms. To violate the licenses one has to alter the content of the track. Zune just marks the track for the 3 days or 3 plays restriction, its not adding DRM on it.

The problem is there are people who want others to share their work for free as long as they keep their name on it. (This is the case with linux for more than 15 years now). No-restriction sharing of CC music on Zune has the disadvantage that there is not an easy way to block piracy. It is very-very easy to add a (false) CC tag on any mp3 file.

CC has a solution for this. The short description is when you get a CC track the Zune could let you play it the 3d3p way. When you get home (or in the future when you connect your Zune to a wireless hotspot) it will check on the owner's site (written on the file's metadata) if the file is really free-to-share and will unmark it.

Of course nobody should expect this in the near future. Zune is an 11 months project. Its time to sit back and do some debugging now. But this is a step to take, if the social is really in Zune's philosophy.

links: wired news | CC licenses FAQ | CC solution for Zune