That was circling the internet a year or two ago.
Oldie but a goodie.
This is how everyone should respond to an AFT agent, attempting to violate the Constitution, and intimidate a citizen into giving up their rights protected by the 4th amendment.
Call Sheriff, express a desire to press charges, formally trespass fed from property while deputies are there, and if you are really feeling sporty, file civil suit.
No crime, no warrant, no respect for constitutionally protected rights.