In Norway, if you publicly perform a recorded musical work where the performer has abandoned all rights by using CC0, or the artist simply declare that the recording is in the public domain, you are obliged to pay a
levy to a solidarity fund for performing artists, managed by the collection society GRAMO. I doubt that performers expected (or wanted)
this to happen. While (AFAIK) there are no similar legal hazard when CC0 is applied to
software, these legal tools tend to lead to unexpected effects and OSI recognizes this problem and do not put them on their list of approved licenses. —
Free Radical 3 hours ago