You can't refuse to be scanned by ICE's facial recognition app, DHS document say

Why exactly have ICE been given limitless power? Facial recognition is at best right more than half the time, but many studies have shown it to be consistently faulty leading to many wrong ID's. What is the point of a database with incorrect biometric data connected to a person?

Because who's going to stop them?

What happens right now is this: ICE can run loose and do whatever they want. If some judge finds their activities illegal, they can block ICE from doing the illegal things.

But...who's going to stop them? Not the DOJ. Stephen Miller has said that ICE have "federal immunity". The keen observer will of course know that there's no such thing as "federal immunity", so a charitable way to interpret that statement is that no-one federal will go after them.

So what about states, and local police? Sure, they could start arresting them, but then again, Miller et. al have warned the states about not interfering, threatening with going after LEO's etc. with federal charges if they do so.

The long story made short is that they can (and will) keep doing illegal shit until someone stops them, and that's not going to happen as long as Trump is POTUS. DOJ and ICE leaderships has explicitly said that their workers should just ignore the law and courts.