Ice can say what they want. The Constitution is the ultimate law of the land here.
Oh yeah, and facial recognition does not work to anything like this degree of accuracy, and probably never can. Nice try.
The supreme court over the years has watered down constitutional protections against government enforcement upon individuals massively because doing so was necessary to empower the government to enforce speeding tickets, financial regulation, environmental regulation, chase bootleggers, etc, etc, with it's power only constrained in practice by political optics.
So now here we are, in a situation where the government is doing what it always does, levying what's essentially a criminal punishment (incarceration in this case, typically fines historically) in a case where allegedly no crime has been committed, and then give the accused only kangaroo court administrative process because it's not a crime, but now it's doing it at scale, flagrantly, loudly and against the political will of some of the locations it's doing it in.
There are a lot of bricks in this road to hell and someone somewhere was issuing a warning as each one was laid. Should have listened.