Years ago I wrote a p2p file sharing program and open-sourced under GPL. Soon a group contacted me for forking the project; I gave them my blessing and wished them luck.
Later I looked at their fork. All they did was adding their names to the copyright and the new project name to the comment section for all the hundreds of files. I was frustrated as this was a clear case of taking copyright ownership for the software. I asked them to remove their names from the copyright unless it's new changes by them but they said GPL allowed it. I contacted FSF for clarification and FSF replied that it's allowed as changing the comment constituted a new change. It's a bunch of BS. It took the rosy glasses off my naive self and soured my view on open sourcing my software in the future.
IANAL, and this is not legal advice, but I am surprised at the FSF's view here. I believed (and believe) that copyright requires a substantive change to form a derivative work, and I would rather doubt that changing the comments counts. (Now, I think that precedents in the court have set the bar for "substantive" pretty low, but not that low.)
I would also say that "legal" is not always the same as "ethical", particularly in this circumstance.
Later I looked at their fork. All they did was adding their names to the copyright and the new project name to the comment section for all the hundreds of files. I was frustrated as this was a clear case of taking copyright ownership for the software. I asked them to remove their names from the copyright unless it's new changes by them but they said GPL allowed it. I contacted FSF for clarification and FSF replied that it's allowed as changing the comment constituted a new change. It's a bunch of BS. It took the rosy glasses off my naive self and soured my view on open sourcing my software in the future.