Letter to the Editor: Install a cashcard machine on supermarket trolleys

Dear Editor, I refer to the article, 'How to get supermarket shoppers to return trolleys?' Why can't they install a cashcard machine on supermarket trolleys, much like the Electronic Road Pricing (ERP) system that vehicles have which are also used for carpark entries? My suggestion: You must return the trolley to retrieve your membership card or ID card. A minister said in Parliament that the police lack manpower. If the police constantly have to investigate lost supermarket trolleys, who is going to investigate other theft cases?