[jonkiddy]

Hanlon's razor. [0]

Assume that the person doesn't know how to correctly contribute code to an existing project. Reach out to them and gently let them know that they are welcome to contribute via Pull Requests. Also, be flattered that someone found value in your work. Assume that the other person simply doesn't know any better. If no response, or no change in a small period of time, then DMCA as mentioned in the other comment.

[0] https://en.wikipedia.org/wiki/Hanlon%27s_razor

[compassios]

Hi jonkiddy,

Thanks for your comment. Do you think that I can do something by changing the license on my open source project?

[phkahler]

>> Do you think that I can do something by changing the license on my open source project?

You can do something about future forks by changing the license on your project. The existing fork was created under the current license on your project and you can not retroactively change that.

[jonkiddy]

INAL. I'm not sure if there is much you can do. If you open sourced the project in such a way as another party can do what they want, we'll expect them to do whatever they want.

[compassios]

I understand. Thanks for your comment!