http://www.ofnumbers.com/wp-content/uploads/2015/04/bitcoinland-april-2015.png
Generated from blockchain data, a little old but interesting still. From the article http://www.ofnumbers.com/2015/04/22/the-flow-of-funds-on-the-bitcoin-network-in-2015/ which is probably more /r/bitcoin than /r/darknetmarkets material.
e; kyc is know your customer. legal.