I am not a supporter of the broad powers given to Federal agents, and it seems likely to me that ICE is overstepping (what I see as) the absurd scope they've been granted by the legislature and judiciary. That said, they don't seem to be "actual, literal Nazis", and I have not seen them "murdering civilians in broad daylight", though ICE do seem to be using the very broad definition of personal protection which has become commonplace (for most police forces).