> The feds in Portland allegedly have the word POLICE on their shirts and that's it. Is that sufficient

Um, yes? That's literally the law. A police officer only has to identify AS an officer. They don't have to identify which branch (police, FBI, etc.) "Police" is enough. Ask any defense attorney.

> It is of unclear legality whether a federal agent can arrest a someone for violating state law

State law? They're literally destroying federal buildings. The federal agents are not enforcing ANY state laws. They are only enforcing federal laws:

https://www.youtube.com/watch?v=5EgMijMhS_U

You assert that they have only arrested people who have destroyed federal buildings? I assert they have arrested people who haven't destroyed a federal building. I assert they've arrested people who haven't violated federal law at all, and that no federal buildings have been destroyed.

Some have almost surely tried to vandalize federal buildings and others who've been arrested have protested peacefully, and still others have only violated state law. None have taken drastic action that would actually destroy a building. I don't care for hyperbole on such serious topics.

All that said I scrolled through your comments. I think at best we won't have a productive conversation on this topic, so I won't invest my time further in it.

If that is true - I can buy a POLICE Velcro badge on eBay, stick it on, and start detaining people? Genuinely, that’d be my fear. I recognize I’d then be impersonating a police officer - but without further identification, there is a huge gap in accountability, right? Someone swipes people off the street - and bystanders have zero recourse to identify and followup on the person detained - they have no idea what agency detained them. That’s how you disappear people.

People impersonate officers all the time - you read about weirdos pulling people over and then getting busted when the drivers calls 911.

It's illegal.

What about this video did you find relevant? The case where one individual attacked a plywood barricade with a hammer and was stopped? (Surely not the Andy Ngo digression.) That's not the topic under discussion. People are concerned with federal officers arresting people off the street with no probable cause.