The utter hypocrisy of American public employees and security cameras

I recently watched yet another so-called "First Amendment audit" video where the guy goes to a public library with a camera and almost immediately gets accosted by the staff for filming, telling him that he can't film there, that he can't film people without permission, and how if he doesn't stop they'll trespass him.

The auditor says to them "but you are also filming people with your security cameras without asking their permission", to which the staff replies with the same response as they always do to such a challenge, in other words, "those are for our safety". (To which the auditor, rather obviously, replied with "and I'm filming for my safety", to no avail, of course.)

This exact same situation, with that exact same answer, happens all the time. Again and again. It's almost like they have been pre-programmed to respond in that manner.

But just consider the utter hypocrisy of that situation. They genuinely seem to be completely oblivious to this hypocrisy and double standard. In other words, they seem to think that they have the right to film people, without asking for their permission, using their security cameras "for our safety", but members of the public do not.

I have never, not even once, seen them explain this double standard. What gives them the right to film people without asking for their permission, while denying that exact same right from members of the public? What's the difference? Where is this exception coming from? Why are they enforcing this arbitrary double standard with trespassing?

And mind you, this is a public place, the publicly accessible areas of a public building, funded by the government ie. the taxpayers. These aren't the private premises of a private corporation or individual. The exact same rules for filming should apply equally to everybody. If they have the right to film people, then everybody must have the exact same right. There is no special exemption where the government can film people without permission in a public building while members of the public can't. Such a law or statute does not exist. They can't just pick-and-choose who gets the right to film in public (especially when they are granting themselves that right, and denying it from others.)

The irritating thing is that also in this case, like always, the auditor didn't press further. He didn't explicitly ask for an explanation for the double standard. He just mentioned it, got the stock reply, gave his stock reply to it, and then just left it at that. I wish someone had an actual conversation with these governmental employees and very explicitly and clearly asked to explain the justification for the double standard.