https://www.si.edu/openaccess/faq
This site includes more than 4 million digitized items and data from the Smithsonian’s museums, research centers, libraries and archives. These items are open for public use under a Creative Commons License 0 that puts this items into the Public Domain.
https://www.sahistory.org.za/policy
This site includes articles, images, videos and other items either created by SAHO researchers and contributors, or collected by the site. Some materials are in the Public Domain, others are under a Creative Commons License, and there are also materials protected under Copyright.
https://www.flickr.com/people/nasacommons/
There is no clearly posted Rights Statement. Each image has a notice about its Copyright status.
The site includes photographs compiled from the archives at NASA images. The purpose of the site is to encourage the public to add comments and tags to the photographs so they are better documented and more easily accessible. There is no general statement on the copyright status of the images. Each image is labeled as either no being subject to known copyright restrictions or subject to some Creative Commons License.
https://www.getty.edu/legal/copyright.html#cc
This site includes digitized images of art works, particularly paintings, ceramics, sculptures, and photographs included in the Getty Museum Collection. The collection includes art pieces from ancient to modern times. According to the Terms of Use of the Museum, a large number of the art images are in the public domain, and this is clearly stated in the Rights Statement of every piece. Some of the more recent materials are under Copyright. The site also provides access to descriptions of the art, text for exhibits and Getty publications. These are described as “Site Content” and are, for the most part, under a Creative Commons License.