Just a few points to add as well. The article is released last year.
https://www.kaspersky.com/blog/bitcoin-blockchain-issues/18019/
Six myths about blockchain and Bitcoin: Debunking the effectiveness of the technology
August 18, 2017
I consider the Bitcoin technology itself revolutionary. Unfortunately, Bitcoin has been used for criminal activities far too often, and as an information security specialist, I strongly dislike that practice. Yet, technologically speaking, Bitcoin is an obvious breakthrough.
It was already debunked by DEA:
A DEA special agent, Lilita Infante, has reportedly admitted that illegal activity is no longer bitcoins primary use. She is part of the 10-person Cyber Investigative Task Force, a team focusing on dark web and crypto-related investigations. The group collaborates with other units of the Department of Justice including the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
https://news.bitcoin.com/illegal-activity-use-bitcoin-dea-agent/The article also mentioned about (psuedo) anonymity, well if he doesn't want to go public because of blockchain, then used mixing services.
