Most of Federal law enforcement except for those that patrol certain, usually sharply defined (but see border patrol for a big exception) areas historically has been in one of two modes interacting: either gathering information (this includes serving a search warrant), or arresting based on an existing arrest warrant, usually from a felony indictment. In the former case, something really out of ordinary has to happen to turn it into an arrest in that interaction (though that doesn't mean you wont be indicted and arrested based on it) and in the latter nothing is likely to deter arrest.

Border patrol specifically is wildly different, looking for people who are suspected of being subject to their jurisdiction without a specific indictment, detaining with in practice, if not in law, a much lower standard of suspicion than applies usually, and then generally having those detained subject to process that is almost entirely within executive branch “courts” with consequences as severe as criminal process but much lower protections than criminal process (where literal toddlers defend themselves in “court" against government lawyers.)

The current “immigration” crackdown, while ICE (which historically has worked more like a regular federal law enforcement agency despite its detainees often flowing into the executive immigration system and not the criminal justice system) has been the public face of it is effectively applying the Border Patrol culture/approach far more broadly (which is also why, in frustration with the “inadequate” results so far ICE middle leadership is being purged and replaced with Border Patrol personnel.)

I agree with all that generally.

There's real serious questions about what rights people have when being accused of non-criminal infractions and to what degree the punishments can overlap that people ought to be asking here.

But nobody on HN wants to ask these questions because all the things HN wants strictly regulated are done so using the same legal theories and doctrines and precedents.