1.Created by the US government

In the mid 1990s, US military researchers created a technology that allowed intelligence operatives to exchange information completely anonymously. They called it 'Tor', which stands for 'The Onion Router'.

As part of their strategy for secrecy, they released Tor into the public domain for anyone to use. Their reasoning was simple: the more people using the system, the harder it would be to separate the government's own messages from the general noise. You can't be anonymous on your own.

Tor spread widely and today, is a critical part of the so-called 'dark web': a network of untraceable online activity and hidden websites, of which Tor hosts approximately 30,000. And that anonymity has attracted a huge range of people; all who want to keep their activities hidden.

2.WATCH: How the dark web works

Watch the video to see how Paul Syverson from the US Naval Research Laboratory created Tor, and how it works.

3.CLICKABLE: Who uses the dark web, and why?

There are many legitimate uses for the dark web- but it also enables online criminal activity. Click on the images below to see how the dark web is used today. 

Contributor: bbc I wonder