Open source authors have always been protective of their copyright. There are numerous examples when drivers have been copied between BSD/Linux (I forget which direction) which led to huge flame wars.

The whole point of the GPL is that it uses copyright and copyright assignment to the FSF to protect what it calls software freedom.

BSD authors are very upset if the attribution clause isn't observed. And so on.

It is communism to exploit poor open source authors? I have to read Marx again.