including that of rick ulbricht, the founder of silk road, serving a life sentence in prison. it enabled buyers to purchase drugs online, to the tune of $200 million, before it was shut down in 2013. the privacy and anonymity game thanks to tor, the door that opens the dark web. it stands for the onion router. and the software includes features that resemble the layers of an onion, helping to provide the cover that makes the dark web a place why groups and people operate outside the law. mary snow took a tour, where almost anything goes, and everything is for sale. >> reporter: on the dark websites advertising from heroin to hitmen, from sex to autognatic rifles are hidden behind layers of anonymity. taking me on a tour, former black hat hacker. >> they are selling sabres, knives, an oozi. >> this is typical of weapons, no background checks, just sell it on the deep web. >> no checks of any kind, as long as you have money. >> the mission of the dark web was to protect confidential secrets and have open source intelligence gathering, and used a programme called tor. using a net