Just can not see the need of secret transactions in the public sector. Besides anyone who thinks that the treasury department, DEA, ATF, FBI, and Barney Fife will not track, tax, and report these transactions is just being silly. Last I checked the IRS doesn't take a fella's word for their income. This whole sector is a lot like the Net's 'Silk Road' it was secret because Law Enforcement wanted the criminals using it to keep thinking that it was secret while they slowly arrested scores of the worst sort of humanity.
All the crypto stuff is exactly the same. One day it's there and thriving the next day it's on the docket.