This happened right in our neighborhood. I happened to catch a creep stealing my neighbor’s Trump sign. He was across the street and jumped into a waiting car when I, 60 years old and 130 pounds, shouted at him. Sure looked like it was planned.
That seems to be their method. Just drive by in large SUV (Ford explorer?). They just stop by the sign, guys jump off, grab them and speed away. Next time, please, make picture of them and the registration of the car. Then inform authorities.