They did that to us in Mt. Airy when they chewed up the streets to repave. They had posted signs, but didn't show up the first 2 days, so everyone blew them off. The 3rd day, at 6:00am, they drove around blaring a siren and telling us to move or they'd move them.
They didn't actually tow them, they just moved them a few blocks over.
-"Grey. You said green men. A Reticulan's skin tone is actually grey. They're notorious for their extraction of terrestrial human livers, due to iron depletion in the Reticulan galaxy."
-"You can't be serious."
-"Do you have any idea what liver and onions go for on Reticula?"