Defining the Deep/Dark Web
There are a number of terms surrounding the non-visible Web, but it's worth knowing how they differ if you're planning to browse off the beaten path. According to PC Advisor, the term "Deep Web" refers to all Web pages that that are unidentifiable by search engines. The "Dark Web," meanwhile, refers to sites with criminal intent or illegal content, and "trading" sites where users can purchase illicit goods or services. In other words, the Deep covers everything under the surface that's still accessible with the right software, including the Dark Web. There's also a third term, "Dark Internet" that refers to sites and databases that are not available over public Internet connections, even if you're using Tor. Often, Dark Internet sites are used by companies or researchers to keep sensitive information private.
While many news outlets use "Deep Web" and "Dark Web" interchangeably, it's worth noting that much of the Deep is actually benign. Everything from blog posts in review to Web page redesigns still in testing to the pages you access when you bank online are part of the Deep and pose no threat to your computer or safety at large. As CNN Money illustrates, big search engines are like fishing boats that can only "catch" websites close to the surface. Everything else, from academic journals to private databases and more illicit content, is out of reach.
Access
Most people who wish to access the Deep Web use Tor, a service originally developed by the United States Naval Research Laboratory. Think of Tor as a Web browser like Google Chrome or Firefox. The main difference is that, instead of taking the most direct route between your computer and the deep parts of the Web, the Tor browser uses a random path of encrypted servers, also known as "nodes." This allows users to connect to the Deep Web without fear of their actions being tracked or their browser history being exposed. Sites on the Deep also use Tor (or similar software such as I2P) to remain anonymous, meaning you won't be able to find out who's running them or where they're being hosted.
Many users now leverage Tor to browse both the public Internet and the Deep. Some simply don't want government agencies or even Internet Service Providers (ISPs) to know what they're looking at online, while others have little choice—users in countries with strict access and use laws are often prevented from accessing even public sites unless they use Tor clients and virtual private networks (VPNs). The same is true for government critics and other outspoken advocates who fear backlash if their real identities were discovered. Of course, anonymity comes with a dark side since criminals and malicious hackers also prefer to operate in the shadows.
Use and Misuse
For some users, the Deep Web offers the opportunity to bypass local restrictions and access TV or movie services that may not be available in their local areas. Others go deep to download pirated music or grab movies that aren't yet in theaters. At the dark end of the Web, meanwhile, things can get scary, salacious and just plain...strange. As noted by The Guardian, for example, credit card data is available on the Dark Web for just a few dollars per record, while ZDNet notes that anything from fake citizenship documents to passports and even the services of professional hit men is available if you know where to look. Interested parties can also grab personal details and leverage them to blackmail ordinary Internet users. Consider the recent Ashley Madison hack—vast amounts of account data, including real names, addresses and phone numbers—ended up on the Dark Web for sale. This proves that, even if you don't surf the murky waters of the Dark Web, you could be at risk of blackmail (or worse) if sites you regularly use are hacked.
Illegal drugs are also a popular draw on the Dark Web. As noted by Motherboard, drug marketplace the Silk Road—which has been shut down, replaced, shut down again and then rebranded—offers any type of substance in any amount to interested parties. Business Insider, meanwhile, details some of the strange things you can track down in the Deep, including a DIY vasectomy kit and a virtual scavenger hunts that culminated in the "hunter" answering a NYC payphone at 3 a.m.
Real Risks
Thanks to the use of encryption and anonymization tools by both users and websites, there's virtually no law enforcement presence down in the Dark. This means anything—even material well outside the bounds of good taste and common decency—can be found online. This includes offensive, illegal "adult" content that would likely scar the viewer for life. A recent Wired article, for example, reports that 80 percent of Dark Web hits are connected to pedophilia and child pornography. Here, the notion of the Dark as a haven for privacy wears thin and shores up the notion that if you do choose to go Deep, always restrict access to your Tor-enabled device so children or other family members aren't at risk of stumbling across something no one should ever see. Visit the Deep Web if you're interested, but do yourself a favor: don't let kids anywhere near it and tread carefully—it's a long way down.