In Finland there is fun thing on that. There is both tickets by municipality where the ticket goes to keeper. But as private parking fines are contractual violations they need to track down or at least reasonably prove the person who parked...

Still, seems to me that it is reasonable to prove who did such violation. Maybe photo could identify person. Or maybe other data could be requested like phone location data. Doesn't seem unreasonable or high hurdle. Probably not cost effective in every case.