I'm not sure the ICE does/did, but remember that "ethnic cleansing" doesn't have to involve (direct) mass murder (even if it often does), for instance the expulsion of millions of Germans after WW2 from their homes (even when they were already living there before Nazis came to power) :
https://theconversation.com/postwar-forced-resettlement-of-g...
Also, Hitler's first planned "initial solution" was, as incredible as it might sound, relocating Jews to Madagascar (which of course would still have caused plenty of misery, since the core issue was that Nazis barely considered them as human beings).
EDIT : Yeah, so after following the rabbit hole for a bit, this seems to be about "Trump's mass deportations". Which I remember him claiming himself (maybe in other words), but one should check how massive exactly they ended to be.
https://theintercept.com/2018/03/26/facebook-data-ice-immigr...
But one of the main gists of that article is about how Palantir is helping law enforcement with data integration. Which, as this blogpost points out, shouldn't be underestimated.
And thankfully at least some of the lawmakers didn't underestimate it : there's a reason why it's illegal to build some national databases, and combine some other less sensitive national databases.
Liberal democracy requires a balance of power, and giving too much power to the policeS (or the state in general) results in a police state (dystopia). (Including through the loophole of private companies like GAFAMs.)
You can also see it as a reminder that tools aren't neutral and scale matters.