There is some good news in the European Drug Report 2016 - but not a lot. So we'll get it out of the way first.

In its latest annual study, the European Monitoring Center for Drugs and Drug Addiction notes a continued decline in the number of new HIV diagnoses among people who inject drugs (PWIDs). The European Union saw the lowest number of PWIDs in a decade, the EMCDDA report, citing figures from 2014. There were 1,236 newly reported drug injection-related HIV diagnoses.

Drug injecting has declined in the Europe Union overall.

However - and we're already into the bad news - the EMCDDA says "stimulant injecting is a concern." Of the people who entered treatment in 2014 with amphetamines as their primary drug, almost 50 percent reported injecting as their "main route of administration."

Drug injection continues to play a "central role" in the transmission of blood-borne infections such as hepatitis C. Some of the highest rates were recorded in Greece, Latvia, Estonia and Sweden.

Drugs of choice

When it comes to the most common illicit drugs in the EU, there's been little movement - cannabis still tops the tables with 83.2 million Europeans saying they've used it at some point in their lives.

Cocaine and amphetamines are ever-present, as are a growing number of new psychoactive substances (NPS), which have been blamed for "acute poisonings and even deaths."

The EMCDDA now monitors more than 560 of these psychoactive substances. Just in 2015, 98 new substances were reported for the first time. This rate has remained steady over the past few years, with at least 100 new substances entering the European market every 12 months.

The return of MDMA... online

But just as new drugs are appearing, old favorites are resurging. The EMCDDA highlights a "return of MDMA," commonly known as "ecstasy" among young people (as well as other things).

"Innovation [...], new production techniques and online supply all appear to be driving a revival," the report says.

The drug's resurgence is exposing weaknesses in existing prevention and harm-reduction methods which, says EMCDDA director Alexis Goosdeel, will need a "rethink."

"This is particularly worrying, since MDMA is moving into more mainstream social settings and is increasingly available via online markets," Goosdeel says.

Most often these online drug markets exist on the "darknet," or deep web. It's a part of the Internet most of us never see if we use "surface web" browsers, such as Firefox, Chrome, or Safari to do things like shop for shoes, stream films or book holidays.

Would legalizing illicit drugs like cannabis Europe-wide help control their use?

These illegal markets can be accessed using the Tor browser, an anonymity network, and the cryptocurrency, Bitcoin. (But beware! It is illegal!)

These markets make it incredibly difficult for the EMCDDA and other agencies, such as drug law enforcement, to monitor, track or shut down illegal activities.

The drugs themselves may also become increasingly potent and, as a result, dangerous. This is not to suggest less pure drugs are less harmful. But recent studies into online drug markets have suggested the quality, or purity, of drugs online is higher than what's sold on the streets. Ironically, this has a lot to do with an idea stolen from legal business models.

As with surface web markets, like Amazon and eBay, deep web markets operate on a testimony-based "trust system," based on reviews between retailers and customers.

If your "product" is no good, word spreads fast, and you will soon go out of business - unless, of course, you up your game, as it were. In many cases, "upping your game" means improving the quality of your drugs.

The EMCDDA monitors drug quality using wastewater analysis. In 2015, a multi-city analysis found the highest levels of MDMA in Belgian and Dutch cities.

"Wastewater MDMA loads were higher in 2015 than in 2011, with sharp increases observed in some cities," write the report authors, "which may be related to the increased purity of MDMA or increased availability and consumption of the drug."

Mapping European drug seizures

But while it appears MDMA is most commonly consumed in Belgium and the Netherlands, it is most commonly seized in Romania and Turkey.

Drug seizures tend to mirror where illicit drugs are produced or where they enter Europe.

Cocaine, for instance, is mainly seized in western and southern European countries, because this is where it usually enters the EU. About 78,000 cocaine seizures were reported in 2014, with half those seizures in Spain. Most amphetamine seizures are in northern and central Europe, and methamphetamine is the most commonly seized stimulant in the Czech Republic, Slovakia, Latvia and Lithuania.

In early June, however, the focus will be online. The European Commission has called an expert meeting to discuss new tactics in dealing with drugs on the Internet.

European Commissioner Dimitris Avramopoulos wants "Internet companies and civil society to redouble cooperation in fighting this global challenge."

Read more on the European Drug Report 2016 on the EMCDDA's dedicated page.