fell off the back of a truck
A reply generally given by bentnose boys to the law-abiding consumer to convince them goods are legit. Now often used sarcastically to refer to stolen goods.
Lula Mae: This TV is very affordable. It's not stolen is it?
Vinny the Mafioso: Nah, it fell off the back of a truck
Vinny the Mafioso: Nah, it fell off the back of a truck