I'll add one. (Not just talking about the immediate employee surveillance tech, but various questionable tech we develop and use, and slippery slopes going forward)
5. Consider the development or use of evil tech to reflect poorly upon the people involved. Like in an interview: "I see you were a developer at Dystopitools..." or "I see you were a manager at Megajerco..."
"I wasn't in the evildoing department" might be an acceptable explanation.
"I was just following orders" seems less likely to be an acceptable explanation.
Asking for an explanation might be reasonable, depending on the nature of the evildoing.
One benefit I imagine of knowing that we'll have to explain ourselves for associating with evil tech is that individuals will even consider that evil tech is a problem. Otherwise, if all people talk about is total comp, tech stacks, and how we spend the gobs of money we get paid, it's easy to forget the inconvenient aspects we don't talk about, like if we're getting paid to do evil.
Of course, sometimes people have no choice. But other times we rationalize, "Sure, I'm actively helping my employer make the world worse, but I have to put food on my family", when there are less-evil alternatives that also pay enough.
(Precedent: I've previously heard multiple executives say they don't want to hire people from particular prestigious tech companies, because, in so many words, they assume that the person learned bad culture at the company, or something is wrong with them for going there in the first place. Adapting that idea to evil tech development and application, and softening it from denylist to being asked to explain, seems worth considering.)
Start stigmatizing evils before a particular kind of evil is so ubiquitous that there are no alternatives.