Copyright replaced, can I put it back and use all code?

Some company took a Zen Cart payment module I created, removed the GPL notices and replaced all original copyright notices by it's own (this includes Zen Cart copyright and my own).

This new version of the module includes some files that I have not created, and I assume they have added those files. Looking at the code, and what their module is being used for, it is also likely they added those files.

Now I would like to use this module and create my own version of it, as intended by the GPL. But I wonder if I can use all included files, including the ones they have added?

paulm:

Some company took a Zen Cart payment module I created, removed the GPL notices and replaced all original copyright notices by it's own (this includes Zen Cart copyright and my own).

This new version of the module includes some files that I have not created, and I assume they have added those files. Looking at the code, and what their module is being used for, it is also likely they added those files.

Now I would like to use this module and create my own version of it, as intended by the GPL. But I wonder if I can use all included files, including the ones they have added?

From a strictly legal point of view you have no rights to use the code that they have created unless they have made it GPL. You could also run afoul of the law using your own code that they have 'stolen' unless you can actually prove that you were the original author.

Also, from a strictly legal point of view they will have broken the law by using your code and removing the GPL.

For either party to exercise their legal rights can be very costly and time consuming though and unless there are $millions involved it probably isn't worth pursuing or defending.

From a moral perspective, you need to ask yourself if you feel that it is right for you to steal their code based on the fact that they stole yours. Only you can answer this question.

The 3rd approach would be for you to contact this company and actually ask their permission if you can use the code that they've developed, and use the fact that they are using some of your code as a gentle persuasion that it would be to mutual benefit that they allow it.

You'd actually be quite surprised at how helpful some companies can be by simply asking in the right manner. Avoid demands and/or threats. Both parties have something at stake and a mutual agreement is always going to be the best outcome.

Cheers
Rod.

PS. This is personal opinion only. I am not a lawyer. I have morals.

Thanks for your reply,

From a moral perspective, you need to ask yourself if you feel that it is right for you to steal their code based on the fact that they stole yours. Only you can answer this question.Personally I don't see me using their code as steeling because they themselves used my/zen-cart GPL code, and thus their code has become GPL too. The fact that they removed the notice and copyright does not change the (GPL) conditions I assume. Of course I have no intention to remove their copyright, I only want to use it to create a fork including their modifications and files.

EDIT: actually I as far I know I can use their modified version of the files I created without a problem, but my main question if I can also use the files they added.

About contacting them: I might give it a shot, but I have had issues like this before, and so far contacting the violators has been a waist of time. That said, you are probably right, and I should try it anyway.

On a side note: I think it will be easy for me to prove I am the original author.

paulm:

they themselves used my/zen-cart GPL code, and thus their code has become GPL tooBOOM!!! and therefore like ANY GPL app, you can FORK it and create a new variation.. So long as you give them credit for the parts they developed. (Much like how Zen Cart STILL has code which gives credit to osCommerce)

In the WordPress world forking happens ALL THE TIME...