A free internet radio program doesn't work very well with closed content.
There are three basic requirements which users should take care of:
The last one is not very common yet, there will probably be a database of such
streams. The first two ones should be requested from all broadcasters, whether
they're free (as in beer) or commercial.
- freely specified transport format (such as HTTP)
- open and patent-free encoding format (such as Ogg Vorbis)
- free content (such as Open Music)