Luckily you can fund the EFF now, all without having to become a billionaire!

Already a member :)

A foundation, just for free software? https://www.fsf.org/

The FSF says they only care about the GNU project license violations. https://sfconservancy.org/ has an actual record of fighting against license violations.

GNU generally requires that contributors assign their copyright to the FSF, which is what allows the FSF to litigate; they can't do this for software that they don't hold copyright to. The Software Freedom Conservancy, on the other hand, holds partial copyright to each of their many member projects' software and chooses to actively enforce the GNU GPL on that code quite frequently.

The SFC's ongoing case against Vizio in California[1] appears to show that violators of the GNU GPL can be sued by users, not just copyright holders. If this case sets precedent elsewhere in the USA and even in other countries, then organisations like the FSF and SFC will have far more options in what violations they choose to litigate. However, this also opens up the risk of 'GPL trolls' who might not be motivated by the same principles[2].

[1]: https://sfconservancy.org/press/vizio-coverage.html

[2]: https://www.fsf.org/licensing/enforcement-principles

Such trolls could only get GPL compliance, not damages though? So not much incentive for them to become trolls at all.

Conservancy do GPL enforcement and you can donate:

https://sfconservancy.org/donate/

Their lawsuit against Vizio is especially interesting:

https://sfconservancy.org/copyleft-compliance/vizio.html