You are free to harass people about licensing if you want, but you don't then get to turn around and claim you're fighting the good fight against overly restrictive copyright law.
If you're litigating against small-time festival organizers for not putting fine print on a poster picture, you're much closer to the Warner Music end of the spectrum rather than the Richard Stallman end of the spectrum in terms of copyright.
Both CC and open-source software use the framework of existing copyright law to guarantee a "fair" use of works, with only few restrictions. Not without any restrictions.
I maybe should not have responded with this provocative question, but to me both movements use very similar tools for similar purposes.
You said it much better than I ever could :). And that's why I used the comparison to the GPL, especially since that has a history of the FSF going to court over violations.