Basically don’t act like a weirdo in the airport (or like a normal person) because air marshals may be following you and documenting everything you do in hopes of discovering you’re up to no good.
That does seem concerning.
Of course the other side of it is that the stakes are high. We don’t want bad people to be able to hijack planes and ram them into who knows what and kill who knows how many people.
That’s never going to happen again because hijacked planes won’t be allowed to fly into cities anymore before getting shot down. Keeping dangerous people out of the cockpit is what really matters in airplanes these days. Airport security is a joke and it’s draconian measures aren’t keeping any of us safe.