The headmaster, Rickard Öh at Nordhemsskolan, is worried that the students in the Majorna-Linné district in Gothenburg are taking more drugs than students in other districts. His call is clear: Parents should take more responsibility.

Police Chief Robin Nilsson agrees.

- I agree with that to 100 percent. Young people have very easy access to drugs from social media and these platforms are used relatively frequently for the sale of drugs.

- There are sales groups both on snapchat, facebook and Wickr Me, says Robin Nilsson.

Hard for police to identify

Robin Nilsson says that the police work with secret coercive measures, but it's not easy. Police cannot breach data privacy and watch chats where they suspect drug sales are going on, without legal space.

"The crime itself, the transfer of drugs, in the basic scale does not reach the penalty that allows us to enter with secret coercive means," he says.

"The seller can work undisturbed"

If so, how should the police counteract the drug trade on social media?

- It is about legislation and it is up to Parliament to understand the problems that drugs comprise in Sweden. If you want to overcome this, you have to look more closely at the legislation and how we should be able to work against it, says Robin Nilsson and continues.

- The lone little seller who uses social media can work quite undisturbed, because it is difficult for us to identify who is behind a certain nickname on a chat, for example.