"Start worrying when it's not a headline anymore."
Er. No? Start worrying before it is not a headline anymore. If you wait to worry (and take action) at the point you propose, it's become too late to do anything about it.
It's sad that this seems to be a prevalent attitude. "It hasn't gotten unbearable yet so there's no reason to take action now." Ideally we'd be pushing back on these things long long long before they're even a remote possibility.
We still have roving packs of ICE people abducting people across the country with almost no accountability. We're not far from "the army indiscriminately opens fire on crowds of people". I like to believe that if ICE were to go even farther and do something like this that it would trigger a mass pushback/reaction, but TBH I don't feel entirely confident that it would.
"Either because the media are suppressed" -- we're seeing media suppression now, from two angles: the head of the FCC is literally trying to intimidate media outlets regularly, the most recent (that I'm aware of) being telling media outlets not to run polls that show how unpopular Trump is. The other angle is allowing the buy-up/consolidation of media by right-wing oligarchs who then start tampering with news coverage.