Look up "Silk Road". It's illegal if what you're buying is illegal. Some of the shops (like Silk Road) only take Bitcoin.
Out of curiosity Ive made a little search for it and it's close now but still transactions there are still continue maybe in other way. I just wondered what items or things that those 5 voters are purchasing there with their bitcoins.
Do not use your bitcoins in Dark Web. Do not feed the illegal network with bitcoins. This activity damage it. Is this use of bitcoin that make that most of the important people that make decisions in our countries define bitcoin as dirty currency.
Definitely will not use it for those purposes. Besides I don't know how to access those deep websites even Google tell me how to do. It's just that I don't want to try even my curiosity always asking me to have a look at that world lol.
If you look at the trial info for "Ross Ulbricht" you will find lists of what was available for purchase. The items sold were no different than what you would find at a Friday night party at any university in the US. 30 years ago at a party, when I was in college, there was an ROTC guy selling primer cord and C4. You used to be able to buy anything at school. The deep web is probably where young university entrepreneurs buy their product. lol
I remember asking the kid why anyone would buy C4. He told me some guys like to go out in the woods and blow up trees for fun. I guess that's why they like to join the military. It gives them a legal outlet to blow shit up and kill things.