The civil engineers in downtown santa monica have engineered a brilliant solution: stencil a scooter and box on the sidewalk. This is some serious space grade stuff considering JPL isn't too far away, unsure if we have the engineering capabilities to apply this solution in other cities. Better ban them outright, right?

In all seriousness, the apps let cities geofence arbitrary areas. You could just spray paint an orderly and designated parking spot on the corner and have the app only let you lock up if you are parked in the designated parking spot, validated with the photo you take after the ride.

Not just strewn with litter, but also more dangerous for pedestrians because many scooter riders use the sidewalks as full-speed slalom courses. If scooters have designated parking spaces and designated non-sidewalk rideable areas/lanes they are great. Most places do not have these things yet and enforcing them takes a lot of the convenience factor away from the platform as well.

So do cars, and somehow they aren't banned yet :(

This is a myopic view. In my city's experience, when infrastructure like parking corrals are provided scooter users tend to behave properly. When there's nowhere to leave your scooter except to balance them in a 5-inch space parallel to the curb, they become disruptive. The solution is to reallocate a minimal quantity of the vast space in our cities we currently designate for the exclusive use of automobiles, not to punish those who chose not to occupy 300+sf of space with their two-ton vehicles.