Why would it be so hard to enforce? Treat the problem, not the symptom. If the problem is that people leave scooters in the middle of the sidewalk, pass a code that says scooters blocking a thoroughfare will be impounded. Don’t mandate to the companies where their property must be stored, let them know where it can’t be stored and hold them accountable thusly.

If Bird had to pay a fee to get scooters out of impound, I’m sure it would find a customer-friendly way to encourage its users to keep the scooters out of impound to begin with.

It seems like this problem is already solved with cars. If you leave a car in the middle of the street, it will get towed. Then the registered owner has to pay a fee to recover it. No worrying about whether to give a ticket to the last driver, or the owner, etc.