How are they not guilty of impersonating the police?

By never claiming they are police.

If their vest said police or had a police badge, or if they claimed to be police, they'd be guilty of impersonating police.

Dressing up in a generic tacticool uniform isn't impersonating police.

They have pictures which clearly show them detaining someone (at least for the camera). I think at some point this crosses a boundary, or at the very least it should https://images.squarespace-cdn.com/content/v1/5e55ad75dc2699....

Citizen’s (heh) arrests are legal (in some jurisdictions and with some restrictions). I’d assume that’s what’s happening in that photo.

I would hope to god one could make the legal argument that one only submitted to the arrest being under the impression they were police officers, and that they were thus impersonating police. Then sue them to hell and destroy the company.

I don’t see how people can build companies like this or work such jobs. It really stretches the limits of human decency.

That's the anarcho-capitalist security model, isn't it?

But if anything actually goes wrong they'll hide behind real security - the government and the police.