If the property owner demands that he take it down, then he probably does not have much legal recourse. I would demand that my rental contract be voided, demand that any deposits be refunded immediately, move out, and widely publicize the fact that only haters of America are welcome in this apartment complex. Ultimately, this will not go well for the property and the owners will only have themselves to blame.
The essential American soul is hard, isolate, stoic, and a killer. It has never yet melted. ~ D.H. Lawrence