I mean, you know how everyone carries a phone these days? If you use your voice, it could be potentially recorded.
So… we could just use sign language. Teach everyone sign language, use that whenever you wanna say something anti-government.
Its much easier to cover up cameras (or move out of sight) than to cover up microphones. And its unlikely people would want to leave their expensive phone in another room out of sight, so teaching everyone sign language seems like a straight-forward option.
Also, bonus: its very helpful for people with hearing problems if everyone knew sign language.
Howbout dunes bene gezeret aproach? As soon as surveillance tech is present use words to talk about whatever and use tiny hand signs that are easily covered up or made nearly invisible to talk the real shit. Might be minimally higher stakes to learn it in the firat place but then…