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