Cannabis is illegal and yet in the UK shops selling cannabis paraphernalia operate openly on the High Street. The "head shop" is an institution that shows no sign of going away, writes Helen Soteriou.
People may not be familiar with the 1960s term "head shop", but there's one in virtually every British and American city.
They tend to make a lot of their money from two categories of products.
There are bongs. Cigarette papers of every size and make. T-shirts bearing the legend "Adihash", in a reference to Adidas's logo looking a bit like a leaf. Steel pipes. Plastic grinders. Rolling "machines" for cannabis smokers who can't be bothered learning how to do it by hand. Sundry caps with Bob Marley on.
The other category is legal highs - drugs formulated to avoid breaching current laws and the subject of perennial concern after a series of high-profile deaths.
One of the last acts by recently departed Home Office minister Norman Baker was to propose restrictions on head shops. He was speaking as part of an attack on legal highs. The substances are a big part of the profits made by many head shops.
"The head shops could be left with nothing to sell but Rizla papers," said Baker.
Despite the prominence of the head shop, they operate in a curious legal twilight.
In the UK, the Home Office states there is no specific definition of "drug paraphernalia".
But under Section 9A of the Misuse of Drugs Act 1971, it is an offence for a person to supply or offer to supply any article that may be used to administer or prepare a controlled drug for administration, if the person believes that the article will be used in circumstances where the administration is unlawful.
On conviction in a magistrates' court, the maximum penalty is six months in prison and/or a £5,000 fine.
Earlier this year, Hassan Abbas, owner of the Fantasia shop in Leeds, and his shop assistant, were convicted of selling, or offering for sale, items which were believed to be used for smoking cannabis. They were fined £800.
Their appeal will be heard early next year, but the case has caused jitters among retailers.
And it has angered activists. "The bongs, pipes, grinders, and rolling papers seized were lawfully bought from wholesalers, having been lawfully manufactured in the first place," says Darryl Bickler, a non-practising solicitor from the Drug Equality Alliance, one of the small groups advocating a change in drugs laws.
"Free thought and expression are being subsumed by presuming criminal intent through 'deviant' association and imagery with simple objects. If the image of a plant offends as used in a particular context, this is censorship of a cultural icon."
The head shop owners are wary of talking about what they do, despite arguing that it is legal. "These guys are understandably concerned as the police are picking them off," says one owner who did not wish to be named. "It is not the responsibility of the shop what a customer does with a product. We make it quite clear they are only to be used for legal purposes.
"All large supermarkets sell king-size rolling papers, which are often used for smoking cannabis, yet I bet they will not ever be getting a knock from the old bill."
For the record, cigarette paper manufacturers like Rizla strongly deny they have products designed for cannabis use. "Rizla King Size rolling papers were introduced in 1977 to reflect the change from regular to king size-length cigarettes," a spokesman says. "They are made for adults who roll their own cigarettes with fine-cut tobacco. We do not condone or endorse the use of our products for any other purposes."
Despite the US's increasing liberalisation when it comes to cannabis laws, people have been arrested over the sale of paraphernalia.
Actor Tommy Chong, star of the cannabis-themed Cheech and Chong movies, spent nine months in prison for his part in a business that distributed bongs and other items of paraphernalia. He says he started a bong company because people were using his name illegally on their own products, so he thought he might as well sell his own.
"I got turned on real early in my life. I was 16 or 17 years old, and a jazz musician gave me a marijuana cigarette."
Chong is in favour of increasing liberalisation. He says people imprisoned for cannabis-related offences are well-behaved. "The police love pot heads too because there is no danger. You are not going to be attacked by some crazed meth freak, you know. Pot heads are very intelligent, very peaceful."
His conviction has not put him off the long-term potential of the paraphernalia business. He wants to create a theme park based on marijuana. "I have always had a plan to do a Hippie Land, you know, like Disney Land. Cheech and Chong's Hippy Land and all that stuff is in the works."
The Republic of Ireland has already changed the law to make it harder for head shops to operate. Northern Ireland's health minister has advocated similar measures.
But the motivation behind the criticism is less about cannabis paraphernalia than it is about legal highs.
"Head shops are not legitimate shops who sell materials that could be used inadvertently. Rather they are channels to sell drugs which go under the misnomer of legal highs," says a spokeswoman for Northern Ireland's Department of Health.
Even for those that don't want the shops banned, there's still a belief that they are acting irresponsibly.
"Our main concern with head shops is the sale of novel psychoactive substances [NPS or legal highs]. Banning head shops would be unlikely to eradicate sales of NPS and runs the risk of creating an underground, illegal network selling NPS," says Alison Christie, policy development officer at Scottish Families Affected by Alcohol & Drugs.
If the shops were banned from selling legal highs, they would be back to relying on cannabis paraphernalia for their profits.
And that may still leave them in the legal firing line.