EFF and sfconservancy exist, they are probably closes to what you can realistically get in this environment. They are are non profits that can try to influence policy but not much more to "protect" individual developers.
Unions (at least in theory) have a way of bringing an employer to the negotiating table by getting a large enough portion of the employees to stop working and bring the employer's business to a halt. in the days of factory picket lines, they were able to prevent other people from working even if they wanted to. this is what gives a union negotiating power. I can't see anything similar for OS developers. What would be the threat? "We'll stop giving you free code?"
regarding a protection union, what you're talking about seems to be legal insurance, and that already exists, but it's significantly more expensive than $20/month.
Unions (at least in theory) have a way of bringing an employer to the negotiating table by getting a large enough portion of the employees to stop working and bring the employer's business to a halt. in the days of factory picket lines, they were able to prevent other people from working even if they wanted to. this is what gives a union negotiating power. I can't see anything similar for OS developers. What would be the threat? "We'll stop giving you free code?"
regarding a protection union, what you're talking about seems to be legal insurance, and that already exists, but it's significantly more expensive than $20/month.