https://www.ice.gov/webform/ice-tip-form

Report them to themselves for human trafficking? Better yet, report a local racist.

Caveat: providing false information to law enforcement is a crime, unlike law enforcement lying to other citizens. In all seriousness, just avoiding them and not aiding them goes a long way, too.

“Have you seen any undocumented people?”

“I don’t know.”

“Have you seen any people?”

“I don’t know.”

“Can you see me right now?”

“I dont know.”

Bonus points if you use “No lo se.”