Last year, police began receiving tip-offs from criminal sources and Customs officials about an increase in suspicious drug-loaded packages coming through the international mail system.
An extensive operation discovered Auckland teens were importing drugs online and selling it to their peers. The Herald on Sunday investigates the world hidden in plain sight - the dark net.
You can buy almost anything on the internet now, from nearly any corner of the planet - it's something teenagers love to do.
Clothes, shoes, books ... drugs, guns, people.
And it's the ease with which youths are accessing a criminal world from the comfort of their parents' living room that has shocked the Waitemata detectives who delved into the realm of the dark net.
The packages Customs officials were discovering were being ordered via the dark web -
a mysterious online world the average New Zealander never sees.
More and more parcels and letters were being intercepted at the border, from such countries as Poland, the Netherlands, Canada, Germany and China.
The source was typical - Customs already had those countries on a watch list.
But the destinations were puzzling - family homes and flats in affluent Auckland suburbs.
Operation Tiger was launched, with Detective Sergeant Tim Williams tasked with leading his tactical crime squad to find those ordering the postie-delivered illicit cocktails.
After months of work and dozens of house searches, the Herald on Sunday can reveal detail of the operation that led to the discovery of hundreds of thousands of dollars in cash and drugs, 13 arrests and a total 79 charges.
Most of the offenders were young, barely out of high school, and in their late teens or early 20s.
Most had no record of any criminal history, Williams says.
Some were still living with their parents, who had no idea about their children's offending and were shocked when police came knocking.
"They were selling to people in their same peer network, often around the same age," Williams says.
"Meth, cocaine, LSD, MDMA, N-bomb, 2C-B, you name it. You can buy most drugs on the dark web."
The dark net is not as hard to find as many may think. Williams learned first-hand of its lure when his unit of five detectives entered that space for the first time.
"In most instances, despite the offender's belief that they were being cunning or trying to use trickery, identifying the offenders wasn't particularly difficult," he says.
"Customs would provide us the information as to the location of where that parcel was to be delivered to and we conducted an investigation based on that information to try and identify who the offender was."
Police say some 90 per cent of the internet is dark. A normal user only accesses about 10 per cent.
Most of the those arrested as part of Operation Tiger had little to no previous dealings with police, were working independently of each other and tried to cover their tracks by using cryptocurrencies.
Bitcoins were most commonly used, which helped to buy nearly half a kilogram of MDMA and 37 litres of gamma-butyrolactone (GBL) from several dark net traders.
"I believe all of them were likely to be users," Williams says, but adds their motivations were financial.
Large profits can be made from dark net imports.
"But like anything it leaves a trace. Using things like Bitcoins allows you to purchase things from the dark net with a small amount of anonymity, but like I said, anything is traceable."
He says often the young offenders lacked social skills and didn't have a large group of friends - many hoped importing drugs from a mysterious web page would make them popular.
"When they got arrested and charged their friends also got spoken to by the police - that didn't make them popular.
"These offenders are completely different to what we deal with. Young and often not committing a series of other crimes," he says.
• Various quantities of drugs were seized during the operation, including MDMA, meth, LSD, GBL, cocaine, cannabis, and amphetamine worth a combined total street value of more than $500,000.
• More than $222,000 in cash
• One property
• One firearm
Operation Tiger, a joint Waitemata Police and Customs operation, was launched last year following the discovery that young people were buying illegal drugs online.
During the six month operation 13 people were arrested, with 12 having since appeared before the Auckland, Waitakere and North Shore District Courts. In June, a 20-year-old Auckland man was sentenced to home detention for importing LSD and ecstasy via the dark net.
Customs manager of intelligence Wei-Jiat Tan says there were certain signs a package or mail had been ordered from the dark net.
"Generally what we do see with dark net seizures is that they're smaller in quantity but higher in frequency."
"There's a number of indicators that we look out for, but I can't go into the detail of those - things that our officers can look out for which makes it more likely than not that it's going to be a dark net seizure."
Customs statistics released to the Herald on Sunday show a dramatic rise in high-frequency, low-quantity seizures at the International Mail Centre at Auckland Airport.
In 2012 the total number of seizures was 1380, but rose to 3166 in 2016.
As of June this year there were already 1162 seizures for 2017.
Dark net seizures are now a daily constant, Tan says, with the Herald on Sunday witnessing several suspected confiscations during a visit to the mail centre last month.
"There's a range of ways that they might be brought through. In some cases they might be disguised, in some times it might be a little bit overt," Tan says.
"We can see prescription medicines, we can see your LSD, ecstasy and cannabis seeds, but you can also see your class A drugs like cocaine and methamphetamine."
Officer experience, training, drug sniffer dogs and intelligence from overseas agencies are all part of the battle to catch dark net imports and identify new trends and methods, Tan says.
"We have a team of specialists who look at gathering and sharing intelligence as well as developing risk profiles, but that's to identify all types of prohibited goods from coming into New Zealand and that includes those coming from the dark net," he says.
The dark net is like the perfect storm, says Netsafe's director of technology and partnerships Sean Lyons.
"The name is so seductive that you get that 'oh my god' reaction," he told the Herald on Sunday.
"We're all familiar with the web now, there are very few people who aren't. But the idea that it's hiding in plain sight of the worldly domain that we could get to, but we don't see, it's quite an enticing idea."
He says the dark net, which was designed to gives users a level of anonymity, was using technology most people were familiar with - but they still didn't know where to find it.
"It's almost like a pro members' club but one that you can chose to join or not.
"There's the web on the surface, there's the web a little bit below that, where we all hide the log-ins and passwords, the place we keep our documents. People say that's the deep web. But even further than that is the idea of the dark web."
Lyons says you won't access the dark web with popular search engines such as Chrome, Microsoft Edge or Firefox.
"You need another level of tool to get there. This other layer is accessed by special browsers and those with the knowledge of where to go looking."
Once a dark web browser is installed and access available, users will search for the right "venue" for whatever takes their fancy.
It's difficult to determine how much of the internet is dark, Lyons says, because its users are constantly adding and removing information in a bid to hide identities.
"To get estimates on how big it is might change on a daily basis. I've seen estimates or reports that the vast majority of the dark net is all child pornography, drugs, or human trafficking, but I think the truth is there are many varied things on the dark web."
The dark web is actually a subset of the deep web, which people are often using for legitimate reasons.
Referencing the Arab Spring revolutions, Lyons says the deep web has been used for hidden communication between people, away from the eyes of oppressive governments.
"We largely celebrated the fact that people were able to express their opinions and overthrow corrupt regimes, and talk without the fear that people were watching them."
However the popular perception that the dark net is a criminal shopping mall has some truth.
"There are book clubs that exist on the dark net, but there are also places where you can purchase controlled substances, where you can purchase weapons, where you can get access to images of child sexual abuse, and where you can literally make bids for the trafficking of human beings."
The premise of the dark web is an online layer built around anonymity - but when someone wants to acquire goods, some of the mystery is lost, Lyons says.
"When a person wants to purchase goods and shares information such as a physical address people are able to be traced."
A danger to the wired generation?
Lyons says the dark web is not something your teenager will stumble across.
"You're not going to one day be trying to find out when the rugby is on TV and the next be on the dark net.
"But that's not to say that a developing adolescent might not have a conversation with his peers to say: 'Don't waste your time on the open web, you want to be on the dark web'."
A danger is teens see the dark net as a playground to prove themselves to their peers.
"I'm going to prove myself by doing X. Some of that may be that I increase my social capital by telling everyone that this is where you can buy drugs online."
He says it's important to talk to young internet users if you suspect suspicious behaviour on the internet - dark or otherwise.
"When they start to hide these behaviours, that's when they run into the risk of being blackmailed or finding themselves in situations where they really shouldn't be."
Late last year, about the same time Williams' team began Operation Tiger, US officials including the FBI initiated Operation Hyperion, a Five Eyes intelligence project, alongside members of the EU's law enforcement agency, Europol.
It was billed as the first step in a unified response to the enormous rise in dark net users seeking to buy and sell drugs and other illegal services.
During Operation Hyperion, New Zealand Police and Customs spoke to more than 160 people across the country who were linked to the dark net, and identified almost 300 involved in illegal trade.
"In terms of the dark net importations it's going all around the country, north and south," Tan says.
"It doesn't matter how big or small the seizure is - this is a serious offence."
Although the legal risks are potentially huge, the consequences to a user's health are also "really dangerous".
"There's a lot of new and untested dangerous substances out there. There's absolutely no guarantee that what you're ordering is what you're going to end up getting.
"They're really gambling with their lives if they're ordering off the dark net."
Police say many of the young people arrested in Operation Tiger showed signs of anti-social behaviour, such as dropping out of sports teams and losing interest in social events.
"If you're directly worried about kids being on the dark net then what you need to be doing is be making sure you're aware of what they're installing on their computers," Lyons says.
"Don't just sit there stewing. Find someone, find a technician who is capable of [knowing what software to look for] and make sure you are aware of that.
"If you look over your kid's shoulder at their laptop and they're using some browser that you've never seen, don't just sit there and ponder over that. Ask them what it is, find out what it is."