The mantra, at least in German hacker scene, is: "use public data, protect private data"

Published data is somewhere in the middle. But open source movement was always around copyright. FSF uses Copyright in Form of "copyleft" GPL for their agenda as does more business focussed open source movement. They are all purposely not using "public domain"

Yes, there is also the pirating scene, "opening" up works and pushing copyright law, but only few advocate complete abolishment of copyright.