This topic has come up a number of times that I’ve seen while doing genealogical research, but I’ve also seen some examples in other areas.
Places like Ancestry.com have images of probably all the US censuses taken. While they don’t claim copyright or ownership, they do say that you can use a small portion of am image, but must get written permission for any other uses
There are also websites that take charts and maps made by the US government and either claim copyright of the image or if you pay for it say you can only use it on one device. Even if that website has just made a direct copy of what is available on the US department that made the chart.
So how does the TOS and copyright, or lack of, change how a document/image can be used? Has it ever come in in court? I doubt Ancestry would come after someone for using a few pages of census records in a book, but what of other items? Say I found a USGS quad not on the USGS site, copied the map and then gave it away. If the place I got the file from can’t really say they own the file can they? Especially if they just took it from the USGS site and put it on their website and said in their TOS it’s our file.