Some 15,000 households in Rotterdam and The Hague are being given ‘scratch and sniff’ cards to help them identify the smell of marijuana, the Telegraaf reports on Tuesday.

The aim is to make people aware of the smell of an illegal plantation, so they can inform the police and electricity company. The card also includes other suspicious signs to watch out for, such as the sound of ventilators and closed curtains.
The cards are the brainchild of the local councils, the government’s anti-marijuana taskforce and electricity distribution firm Stedin.
Dangers

If it is a success, the scheme could be extended nationwide, Stedin director Jeroen de Swart hopes.
Illegal plantations are often a source of house fires because they use huge amounts of illegally-tapped electricity. They can also cause water damage because of the automatic watering systems.
Though it remains technically illegal, the Netherlands turns a blind eye if people grow up to five plants for personal use.
Cash crop
However, the illegal growing industry is thought to be worth some €2bn a year, and has become a focus of police attention in recent years.
According to the Telegraaf, some 40,000 people are involved in marijuana cultivation and some 5,000 plantations are busted every year.
In July, police dismantled a massive marijuana plantation with 10,000 mature plants and one million cuttings in a greenhouse complex.