To access the dark web, one needs a special type of anonymization software found on the internet. Tor is a good example of such software. Using special Tor addresses and the Tor browser, one can anonymously connect to these "dark" web pages and surf them.
Cyberexperts say the dark web is used by a range of bad actors. But it's also been used by whistle-blowers as well as activists during the Arab Spring, who harnessed the platform's power to organize demonstrations and disseminate information anonymously.
I think illegal activity on the dark web is the biggest danger right now. Clearly, we want to have a dark web that provides privacy guarantees for users, but at the same time, we don't necessarily want this technology to be misused for illegal activity. There is no easily solution I am afraid. This discussion is the same discussion that we have around encryption. Governments would love to read every encrypted communication.