I was once asked by a boss to write code that I felt was unethical. I don't remember exactly what it was now. I do remember that I managed to convince them not to do it by finding a (probably) better way that didn't challenge my ethics. Had I not managed to convince them to do it ethically, I don't know what they'd have done. But I'd already told them that I wouldn't do anything unethical when they hired me, and I told them that their solution to that problem was unethical.

It wasn't even anything important. It was only "a little unethical" and wouldn't have really affected many people negatively. But the line for me isn't how unethical it is, just that it's unethical at all. I simply don't need that in my life, no matter the price.

I wish more people would draw the line where I do, but I do understand the conflict and why they might choose otherwise.