The dark web isn't just for buying drugs and hiring assassins. It's a massive network of websites and communities that exists outside of mainstream internet culture, and there's plenty to do on the dark web without breaking any laws - from book clubs to crisis preparation.

Privacy advocates love it. Law enforcement hates it. The Tor web browser is especially designed to provide web users with a a completely anonymised online experience - and it recently received a big new update. But what is Tor? Why do we need it? And is it actually worth using?

Certain users of the privacy-minded Tor web browser should download the app's latest update, which adds a temporary fix to prevent the browser from leaking identifying information, namely IP addresses. The TorMoil bug, as named by the security research company that discovered the vulnerability, We Are Segment, can take advantage of a flaw in the browser to uncover a user's real IP address, outing anonymous browsers should they click on a particular type of link.

It turns out your browser's privacy features aren't as anonymous as you think. Although Ingonito mode on Chrome, InPrivate with Edge and Private browsing with Safari make it harder for someone to view your browser history on your device, they don't hide your browser habits completely.

Whenever your computer visits a website, that traffic can be recorded and linked back to you directly. So, what can you do to be totally private on the web?

If you've been thinking about trying out Tor to anonymise all your web browsing, you could just download a browser and give that a spin, but it's much more fun to make your own highly portable proxy that you can easily connect to on a whim. Enter the Raspberry Pi.

The Silk Road trial has concluded, with Ross Ulbricht found guilty of running the anonymous online marketplace for illegal goods. But questions remain over how the FBI found its way through Tor, the software that allows anonymous, untraceable use of the web, to gather the evidence against him.