Electric scooter rentals are taking over cities worldwide. In Vienna there are more than 6,000. But more e-scooters, mean more accidents.Vienna responded accordingly: e-scooters must follow bicycle rules, obey speed limits, stay off the sidewalks, and avoid drunk driving. And now there are even Scooter Sheriffs, who move incorrectly-parked scooters, pick up fallen ones and caution riders caught parking improperly.