Unruh, W.G. 2008 Physicists and copyright - How to give away your birthright for what?. APS News 17(6)8.
Draws attention to the consequences of some journals' copyright transfer agreements which mean that "derivative works" which "depend on" the original need the permission of the copyright holders and urging authors to scrutinize such agreements before signing and not to sign those that do not specifically allow the authors to make derivative works, in any context, commerical or non-commercial. On the same page Gene D. Sprouse (Editor in Chief, APS) and Joseph W. Serene (Treasurer/Publisher, APS) reply under the title A response from APS to say what the American Physical Society's position is and why they believe their current policy is defensible. They also refer to a list of "frequently answered questions" on their website: http://forms.aps,org/author/copyfaq.html.
Posted for John Glen