“ResearchGate still infringing copyright, publishers say” (News, 11 April) misuses the term “public domain”, making it sound as if whatever is freely accessible on the internet is “public domain”.
“Public domain” is when copyright has expired at the end of its term; this is the traditional definition. A more recent definition would also include when copyright owners waive their rights and place their work in the public sphere from the start, using a Creative Commons designation.
The papers that the Coalition for Responsible Sharing wants to have removed, if they are infringing on copyright, were never in the public domain in the first place. So they cannot be “taken down from the public domain”.