As noted here recently, London's National Portrait Gallery is involved in a legal tiff concerning whether the photos it put online of public domain portraits are public domain
themselves. The Gallery insists they are not, and wants to prevent others from using them. However, jump across to this side of the pond and compare that response to what the Smithsonian is now saying, concerning its plan to get content more freely available and shared
Content Usage: Establish a pan-Institutional policy for sharing and using the Smithsonian's digital content, with particular focus on Copyright and Public Domain policies that encourage the appropriate re-use and sharing of Smithsonian resources.
That sounds a lot
better, and more in-tune with the mission of such a museum. To be fair, a few years back, the Smithsonian had its own troubles
claiming copyright over public domain images, so perhaps it just takes a bit of time for these things to sink in.