Although I am picky about copyright issues I do wish that federal government sites would not post old photos then claim we cannot use them AND make it impossible to do so by means of a watermark. An example of this is the U.S. Army's history outfit at Carlisle Barracks. I understand that a portion of their Civil War photos are "on loan," so to speak from a Massachusetts lineage group. However, their generic "Civil War photos" with no attribution or restrictions noted also have big stamp on them saying that they came from the US Army Heritage and Education Center, don't touch! Unless they can prove these photos are NOT in the public domain - and maybe they aren't - they should not prevent fair use of these photos. They are 150 years old and no provenance is given, that I can see. [I do not know why this is showing up in italics, sorry.]
The author is an Arizona research historian who enjoys the challenge of looking for Mayflower descendants, hers and anyone else's.