That’s fair, but it’s still an unsavory argument style. “I know the secret motivations of those in power, which even they don’t know”. It’s a weird way to remove agency from the powerful in the name of, IDK what.

I think hide implies intent to deceive. It's often more like conscious and sub-conscious reasoning. We constantly tell a story to ourselves about our motives. We're impulsive and wrong a lot of the time. And nobody is the bad guy in their own story.

Maybe it's willful ignorance. Ignorance of the misuse and harm of mass surveillance.

Maybe. Are you as open to the idea that those who oppose surveillance (that’s me) also have secret motives and engage in willful ignorance, so you can’t trust my anti-surveillance arguments? Because, the theory goes, even I don’t know the dark motives that are making me say those things?

Do you see how impossible any dialog becomes in that model?

If you frame it as ignorance, the next step is to enlighten the other side with the factual arguments you want to make. "The threat landscape isn't as bad as you claim it is." "Mass surveillance has downsides that are worse than you would think." If you assert deceptive intent, it kind of slides into character attacks.

It's true that people sometimes don't argue in good faith, and it's fair to question hidden motives. But I think if you have better facts, you should keep arguing the facts.