This was written in the book Star Trek Memories by William Shatner and made me pause. But today we are seeing it happen in real time in America and yet no one is truly trying to stop it. So with this we can see exactly how it could happen then.
Hell the media alone refuses to acknowledge we have Concentration Camps in the states.
Some places make it illegal to harm said geese. You will then notice said geese are only aggressive in those places. Because they know the humans can't fight back.