A joint report on cryptrocrancy firm, restrictions and illegal finances and oval specializing in forensic sciences said that detection of bitcoin was a highly centralized process for illegal drugs activities. The authors of the report, Yaya Fenussi and Tom Robinson, indicate that many illegal bitcoins are bleached by blanders, SOURCE https://cointelegraph.com/news/new-report-bitcoin-drug-money-laundering-is-highly-centralized