Regardless of the legality (which I can’t comment on being on the other side of the pond) - masked anonymous people snatching people from the street and disappearing them in unmarked vehicles sounds A LOT like what the nazi party did in my country. I know it’s a tired trope by this point but the parallels are definitely there.

And you know how the saying goes: first they came for xyz, by the time they came for me nobody was left to speak out for me.

US America was always a place for me to look up to, for free speech and a humane society that welcomes everyone — even if that was always an unreal ideal but at least it was something most US citizens took seriously; really sad to see it being dismantled so quickly in the years after 9/11 leading up to the situation now

In terms of armoring the argument, I try to add a time component: "That's exactly what the Nazis in $YEAR."

Granted, this won't work on people who don't know or care about history, but that was probably a lost cause anyway.