Hypothetically, I imagine community group chats, whose members also text warnings to other locals not in the chat, and those people then spread the word further. When agents are seen lurking around town, someone sends the word out, and maybe people can even gather in person and follow the agents to warn passersby, film any arrests, remind people of their rights, and protest.
What’s legal and what’s not?
If plainclothes officers knock on your door use the libertarian defense saying you thought they were intruders and dome them.
Pigs of the state don’t deserve our empathy.