Fuel price rises have caused an explosion in the occurence of number plate theft. Unable to buy false number plates due to tightening up of legisltaion governing the supply they steal them off cars instead. They are normally stolen in order to disguise a car when it is used in a fillng station drive off without paying. These crimes only amount to £100 or less but are so easy to commit. It would take very little to dissuade the potential thief, attaching the plates with tamper proof screws would be enough but it would have to made compulsory to be effective.