More than two dozen cannabis-selling coffee shops in the south of the Netherlands are to become private members clubs in a bid to keep out foreign drug tourists.The coffee shops in the province of Limburg will start issuing membership cards at the beginning of next year. Applications would take several days to process, thereby thwarting short-term visits. An estimated four million foreigners travel to Limburg each year to buy cannabis. The measure, which applies to all establishments on the border with Belgium and Germany, is backed by the national government. It is seen as a pilot project for possible expansion to other areas. Dutch law prevents the mass cultivation and retail of cannabis. But a daily possession and consumption of five grammes per individual is allowed.