If that were true, they'd be showing up with real warrants (super easy if these are convicted felon illegal immigrants as they claim! But of course there are nowhere near as many of those as, say, the "thousands" they claim exist in Minneapolis) and mostly dressing in much more ordinary federal agent clothes and it'd all be boring and uneventful and legal enough that most of what they're doing would hardly even be noticed.
Going several thousand(!) strong into a US city and rolling around town in paramilitary convoys questioning people who don't "look American", to... "support fraud investigations" apparently, LOL, WTF... among other things, is why they're a hot topic right now. If they were doing what they claim to be doing, this would all be boring stuff.
Frankly I don't feel like I should be having to explain why guys in SUVs wearing plate carriers and comically overloaded with blinged out Call of Duty gear driving around a US city and sometimes jumping out literally going "papers, please" to people who "look foreign", all while universally masking up to hide their identities, is extremely fucking bad, to the point that I think that language is way too mild, but here we are I guess.