Dutch on scent of dope farms

Police in Rotterdam and The Hague have mailed 30,000 of the cards so far.

Dutch citizens can grow up to five cannabis plants for personal use. But energy firm Stedin is sponsoring the cards in a bid to stop dealers siphoning off power to hothouse their crops.

"From now on, you'll be able to smell the possible danger of an illegal cannabis crop in your neighbourhood," the card says.