If this is your private property, put up Private Parking and No Trespassing signs. Also, put up the No Parking-Violators will be towed at their own expense signs. Take pictures after you put them up. If the scooters are parked there for 3 days (after taking photos every day), call a tow company to have them towed/taken away at the owner's expense. Not your fault. The scooters get moved and the idiots who don't care about your property pay the cost.