Suppose I have a software program I publish under a non-free license that does not give permission to create derivatives, and I own the copyright. Someone decides that despite the copyright they are going to make a derivative of it anyway. My question: If this happens: Do I own the derivative that the person made? Could I take the derivative and publish it under an open source license?
Do I own derivatives of my copy written work? Can I make these open source?
proprietary code;derivative works