These are about violation of GPL, none of the suits was filed by individual developer who was contributing to the code base. Show me better examples.

> none of the suits was filed by individual developer who was contributing to the code base

(You're not implying otherwise, but this seems like a good place to put this comment.)

An individual developer can bring a case against a distributor violating the GPL if they can prove that their code was involved in the violation.

A good example are the contributors who brought a Linux (kernel) case against VMWare:

https://sfconservancy.org/blog/2016/feb/29/vmware-hearing/

> none of the suits was filed by individual developer who was contributing to the code base

Isn't that what actually happened in the GPL-Violations.org project with netfilter?

It makes me happy to see this. But still I'd advise using developer agreements, if you want the control of the project. And correct license of course!

And it's proof that like Oracle suing Google over 10 lines of code, it's enough for one or more contributors to claim ownership of some (small) part as a basis to take, say, Netgear to court. Thus you don't necessarily need to assign copyright over to a single person or organization.