This decision to use a CC license grew out of the concept of OGD, Open Government Data. These municipalities have also just established the “Cooperation OGD Austria” – a new alliance bringing together governments on all levels to forge common standards and develop conditions in which OGD can flourish to the benefit of all stakeholders. OKF Austria will be acting as the advisory member to the new group.
The US actually has a similar idea written into law. The federal government is denied copyrights on documents it produces (there are exceptions). Curiously enough, that little bit of copyright law is not in the US Constitution. It's only a law, which means it could be repealed or overturned (we have a nutty Supreme Court right now).