This is sort of like saying "it would be nice to have a concrete proof that P = NP." Determining what's right and wrong is the major endeavor of several entire fields of scholarship. No one can give you the ultimate answer to this question. You can develop your own approximation of the answer by empathizing with other people and reading lots of philosophy, literature, and history.

I think Mozilla is trying to remind techies to think about ethics for this exact reason: a lot of us have this weird mindset where, unless we can define something with mathematical precision, then it doesn't exist and we don't have to worry about it. This is an incredibly unhealthy way to think about ethics, and it's one of the reasons why our field is sliding towards a bad reputation.

I sort of agree... but I do think its worthwhile thinking about best practices around ethics and writing them down somewhere for all to see.

The GDPR does a decent job in this regard around privacy and data use. Can we write a similar document to GDPR around other ethical concerns?

Great questions!

I think it's fine to try to raise awareness of this issue simply as something that younger folk/people starting in their career should consider, if they haven't already. But yes, if they do consider it, also try to get as much information as they can before making decisions. Also I don't agree with pointing fingers at certain companies simply because that's a popular thing to do, you need a lot more data to back up statements such as "big company X is evil", it may take months or longer to go through all that data and get some objective answer to the question. Otherwise we're simply doing gut/feeling based selection, there's nothing inherently wrong about that but we should admit it to ourselves then.

I'm not sure I have the knowledge base to fully answer your question but one thing to consider is that no matter where you work, if you dig deep enough you'll probably find something unethical (and some might say if you don't find anything, you're not really looking). I mean under capitalism we're all working for just enough to survive and maybe retire on while our bosses take home the fruits of our labor, so we can start from there and conclude there's really no fully ethical job.

What's most important is finding out the core business models your company is aligned with, and who they work for. For example, if you thought Google was a fundamentally evil company (I'm not saying you or I think that, just an example) then by working on Angular you'd be helping to legitimize Google as a business that does a lot of good things. This will ultimately make it much harder to build a popular movement around stopping the evil Google.

You can see this play out in real time right now as Palantir and ICE try to rebrand as companies/agencies that sell/use tools which combat child trafficking. This may be true, but they also terrorize immigrant communities and must be stopped.