In the 1988 case California v. Greenwood, the U.S. Supreme Court held that no warrant is needed to search or seize garbage that is placed on the street for collection, as there is "no expectation of privacy".
Where I lived in the 1980s, garbage cans did not need to be taken down to the street. They merely needed to be placed outside, on or near the driveway. Garbagemen drove motorized scooters (like the Westcoast Mailster, but with an open hopper on the back) up driveways, got out, dumped the garbage into the hopper, and then drove off to the next house. (Eventually the scooters would transfer their load to a full-sized garbage truck.) The garbage cans never left the proximity of the home (not even 10% of the distance to the street), and never left private property -- not the street, not even onto a public right-of-way. However, the garbage cans were visible from the street.
Is a warrant needed for search or seizure while the garbage is still on private property, as in the garbage cans in this situation? (I suppose authorities could wait until the scooter returns to the public street with the garbage, but that's not what I am asking here.)