Political dissidence isn't always due to a person being a criminal, sometimes it's just because the country that classes them that way are extremist in their own position. So much so that "Free Speech" and "Human Rights" can be seen criminal.
Primarily for unmonitored communication, I'd think. The wiki is sort of misleading. Normally, unencrypted web services are on TCP port 80, but you could set your server config to listen on port 10800 for example. Your client would then connect like so: [noparse]http://darksite.net:10800[/noparse]. Certainly you could have secure protocols, but key distribution would be a bit trickier..
Some countries use it as a means of communication that is not monitored and regulated (like certain citizens using TOR) some use it as a means of accessing otherwise inaccessible sites due to heavily regulated and monitored internet (countries with regulated/monitored internet and no freedom of speech or freedom of religion, etc) such as using TOR to go to the internet to search for USA news in countries where this is prohibited or punished when found out and like any such thing where secrecy and stealth are concerned, there will be spies, criminals and the like using it as well then there are the people who are paranoid or the seditious rank and file illicit affairs or the uber geek looking for a thrill or political / corporate espionage like Dr. Toad says... primarily for unmonitored communication (for whatever reason)
If you count using proxy IP's as using the darknet, then it is essential for many people. Anyone who wants to say something for which they could be arrested. Anyone in a country where internet content is blocked.
