ProPublica did a story on this type of stuff. There have been many instances of ICE agents doing "mass deports" where they round up groups of people and deport them all. It's hard to keep track of this sort of thing but likely hundreds of people with full citizenship and mental disabilities have ended up deported to a country they know nobody at. Not that the fact that they're us citizens makes this any more fucked up, but it highlights how much power they really have

The ICE director has repeatedly made statements under the Trump presidency that they believe the organization is above federal law (like the army) and only beholden to the president's orders