These guys have it down to a fine art and once the initial wheel clamps are in place there is no turning back, as far as the authorities are concerned.
Whereas a traffic warden or police officer has jurisdiction over public roads, in many countries, the law allows landowners to wheel clamp vehicles parking on their property without permission.
The deterrent can take physical forms such as vehicle immobilisation exemplified by the wheel clamp and non-physical forms such as levying parking charges to the registered vehicle owners.
Despite a forensic examination of the wheel clamps that had been securing the caravan the offender was never traced and the vehicle was never recovered.