The dark web is a non-mainstream part of the internet. Basically, it shows those search results, which are not indexed by search engines such as Google and Bing.

It requires special software to access. Once a user is inside the so-called dark web, he/she can surf websites and other web-based services can be accessed the same way a user access the web usually. The dark web is used for selling illegal drugs and firearms, payment for which is received in cryptocurrency such as Bitcoin.

An important thing to note is that the dark web, which is also known as the deep web is also used for manipulation and even hacking of cryptocurrency.  Users can also purchase fished credit card information.

That being said, unless you are using the dark web for illegal purposes, just accessing un-indexed search results is not illegal, but what you view or purchase will determine the legality.

Read: Phishing Scam: Man Stole Bitcoins From Dark Web Forums

There is also a lot of depraved content available, which might not be illegal but still extremely creepy.

Also the dark web has also been used for surfing child porn, for which a person was arrested in the U.K. on Friday. Surfing the dark web in no way means that you are out of the reach of the law. Many U.S. agencies have agents surfing the dark web — someone you meet in a dark web chat room might be a cop. In fact, an FBI agent recently revealed that a coordinated international police investigation took down dark net marketplaces such as Alpha Bay and Hansa.

Andrei Barysevich, director of advanced collection at threat intel firm Recorded Future, said about the takedown, "The coordinated closure of two of the most popular underground marketplaces shows the level of sophistication and, most importantly, the willingness of international law enforcement agencies to combat cybercrime jointly."

"The successful takedown of AlphaBay and Hansa marketplaces – the largest police operation since SilkRoad – has already significantly disturbed the underground economy, and I expect to see the level of cybercrime go down in the short term. Despite recent news, we don't expect criminals to abandon dark web marketplaces, as the business opportunity of exposure to hundreds of thousands of buyers is too lucrative, and as we have seen before, eventually new market leaders will arise, filling the void."

If you do plan to use the dark, the most important thing would be to proceed with a lot of caution. In the dark web chances of being scammed out of your money are even higher than the regular internet. One thing you should do is to cover your webcam with tape, as you might be secretly recorded.

Also, never download any software or plugin from the deep web as it could be used to hack into your system. Also don’t access your private documents while surfing the dark web. The ethical status of dark web is also controversial. According to privacy activists such as the Electronic Frontier Foundation, users of the dark web are just people concerned about their privacy. With revelations of government snooping by agencies such as the NSA, FBI and CIA, this is not surprising.

Read: AlphaBay Offline: Dark Web Market May Have Disappeared In Bitcoin-Stealing Exit Scheme

Journalists, to contact whistleblowers and activists including Edward Snowden, have used the dark web in the past. That being said, a cursory glance at any databases of dark web websites will reveal that it is being majorly used for illegal activities.