On July 1, it was reported that the amount of Bitcoin spent this year on illegal activities was more than $500 million, and it was expected to reach $1 billion by the end of the year, which would be a record amount. Though, at the same time, the actual percentage of illegal Bitcoin transactions has fallen.

According to Hannah Curtis, who is an executive at Chainanalysis — which is the company that issued the report — while people so far this year have spent $515 million worth of Bitcoin on illegal activities, this represents only 1% of total Bitcoin transactions. To put this number into perspective, back in 2012, 7% of all Bitcoin transactions were spent on illegal activities.

Chainanalysis says that the $515 million worth of Bitcoin that was spent illegally was done so on the so-called Dark Web. This is a hidden part of the Internet where web servers have no definable IP addresses and hence cannot be easily traced by authorities. It was on the Dark Web that Ross William Ulbricht infamously once ran Silk Road, which was a popular place to buy illegal goods with Bitcoin until the U.S. government arrested Ulbricht in 2013.

Currently, the largest illegal marketplace on the Dark Web that allows Bitcoin payments is called Hydra. Chainanalysis says that Bitcoin is the most popular form of digital currency on these sites, following by Monero. Chainanalysis also says that the most popular forms of illegal activities on these sites are drugs and pornography.

In April of this year, the two people who were running the Dark Web site NextDayGear agreed to plead guilty to various charges, which included the selling of such things as controlled substances and laundered money. Among the products on sale at the site were steroids, Xanax and Valium. They were also illegally selling Viagra.