that's a common misconception about at will employment. at will is pretty fucking stupid, but you do still have some protections. if you have them on record 1) praising your performance and 2) saying things like [apologies for the transphobia that's about to follow; I'm trying to give an example of an offensive quote] "you're a man. you can't wear nail polish." , that can absolutely be enough to make a case for discrimination. At will means they can fire you without a reason. It doesn't mean they can fire you for ANY reason. that's a really important distinction.

Now, the problem with such laws, of course, is that you often have to be in a privileged position in the first place to be able to get them enforced. So it is a catch 22. But pro bono lawyers are a thing, and also sometimes simply showing that you know your rights can preempt any problems to begin with. For example, when talking to an old apartment complex I lived at, I casually mentioned to the property manager how weird it was that the black families I'd talked to were getting quoted higher renewal prices than the white families... that shit disappeared real quick, even though none of us were actually going to lawyer up.

Threatening people rarely goes well. but I've had a decent amount of success with a sort of playing-dumb "I love this company and I'm sure it's just a big misunderstanding. I know you guys aren't the sort of people who would mean to violate the law like [way you violated the law yesterday]. that's why I wanted to bring it to your attention--for everyone's benefit, so we can keep doing great work together."