In November, the UK government announced the formation of a specialist cybercrime unit. Its mission: to tackle the Dark Web, where all kinds of things happen shrouded in secrecy.
The Dark Web's ecommerce is usually illegal, and the things being shared by its users are often appalling. The most recent claim, which appears to be true, is that the Dark Web is being used to trade AK-47s in Europe. It may even have played a part in the recent Paris terrorist attacks.
- Related reading: Who's watching you online and how to stop them
Dark Web. Deep Web. Darknet. What's the difference?
The Dark Web is sometimes confused with the Deep Web (sometimes called the Darknet), but while there's some overlap they're two very different things. The Deep Web is the internet that search engines don't crawl: not just secret web servers but your private webmail, companies' databases, your private cloud storage, members-only online forums, your online banking and so on.
Most of the Deep Web is perfectly legitimate and hidden from search engines for perfectly sensible reasons. That means that the Deep Web includes the Dark Web, but the Dark Web is only a small part of it - although that doesn't stop excitable newspapers from trotting out scare stories claiming that 90-something-percent of the internet is the Dark Web. It isn't.
Okay then, what is the Dark Web?
The Dark Web is the bit of the web that's deliberately hidden to prevent people knowing what's going on there. For example, if you're a political dissident in a repressive regime you would use the Dark Web to prevent state snoopers from spying on your online conversations. Inevitably it's also used by people who have to hide their actions for less noble reasons too.
Should I visit the Dark Web?
For most of us, the short answer is that there's no reason to: unless you're really paranoid about your privacy or you're doing something that really needs anonymity, such as reporting on repressive regimes or crime syndicates or trying to bypass state censorship, there's no real reason to venture onto the Dark Web at all - not least because it slows down your browsing.
There's a fascinating thread on Reddit (not remotely safe for work) where Dark Web users share their stories, and some of the tales are enough to make you tape over your webcam and disable your router just in case. Think of it as the dodgy bit of town where sensible people don't go after dark.
If that's just made you more interested, the key to the Dark Web is Tor. You can download it from Torproject.org.
What is Tor?
Tor stands for Thin Onion Routing, and in 2013 UK MP Julian Smith described it as "the black internet where child pornography, drug trafficking and arms trading take place". He's not wrong: Tor is where the now-defunct Silk Road drugs marketplace could be found, it's where Black Market Reloaded traded drugs and weapons, and it's where the US National Security Agency says "very naughty people" hang out. It's not the only network on the Dark Web - for example, you may have heard of the Freenet anti-censorship network - but it's by far the most popular.
According to an investigation by Deep Web watchers Vocativ, European terrorists who wanted guns used to "tap into a 20-year-old market that took root and flourished at the end of the Balkan wars. Now with the rise of the dark net, that market has been digitized and deals on illegal guns are only a few minutes away." Many of those deals are from people in the US: Vocativ found 281 listings of guns and ammunition on the Dark Web, the majority of which were shipping from America.
It's not that Tor is evil; it's just that the same tools that protect political dissidents are pretty good at protecting criminals too. That wasn't intentional. Tor was initially developed by the US Navy, and its goal was to protect internet users from spying. It does that by bouncing users' and sites' traffic through multiple relays to disguise their location. Other than "very naughty people", it's used by political activists and dissidents, journalists, people who don't trust websites' use of their personal data and the odd member of the tin foil hat brigade.
If the Dark Web is so secret, how does anybody find anything?
That's a very good question, and for many people the answer is Reddit. Subreddits such as DarkNetMarketsNoobs exist to guide newcomers around the Dark Web, while on the open web certain Wikis are a kind of Yahoo! for destinations on the Tor network - albeit a Yahoo! where many of the links are likely to land you in prison, which is why we aren't naming or linking to them.
You'll see that the sites have the .onion extension: that means you need a Tor browser to open them. You'll also see that the majority of sites you can find are marketplaces, because those sites want to attract as many customers as possible. That means they're the tip of the Dark Web iceberg, as many sites are secret and only available to people with the right credentials and/or contacts.
Can I protect my privacy without going onto the Dark Web?
Yes. While Tor is a powerful tool for protecting your privacy it isn't the only one. Encrypting files and anything else important with an open source encryption method (so you can be sure there aren't any back doors in there) is one of the strongest privacy protectors, while privacy-focused browsers such as Epic and Ice Dragon remove the most common features used to track users such as IP address tracking.
If you just want to stop ad networks tracking you, plugins such as Ghostery can block trackers and other potential privacy invaders while secure VPNs can anonymise your browsing. But don't forget the basics, either: if you're dealing with documents that could make you the next Edward Snowden, use an "air gap" - that is, a device that isn't connected to anything else at all. Your data can't be intercepted if you aren't on the network.