Under U.S. copyright law, the creator of any original work has a copyright in the work. Yes, you can't copyright someone else's work, but you can modify it and create an original work. There is an internet business that takes artwork created by others and adds funny quotes. It is causing quite a sensation in the arts community, but apparently the new creators have been found by some courts to have created a new work that the original artist can't block. I worked on a case 20 years ago involving a company that made gold record plaques out of phonograph albums (to be sold in frame shops). In New York, that was allowed. In Los Angeles (a different federal circuit) is was considered a copyright infringement.

There are also cases establishing that a photo of an ordinary object without any creative input cannot be copyrighted because there is no creativity. A lot of scanned items are falling within that category.

The internet has affected how people behave, but it has not changed the law. As always, attorneys who specialize in intellectual property should be consulted. It's not an area I practice anymore, so while I read some of the big cases that come out, I do not keep track of everything in the field.

(I was one of several lawyers that represented the Peanuts and Garfield comic strips and the rock band Badfinger many years ago)