This article has a clear contradiction. It speaks of the fact that they are using BTC as a tool of privacy and hence out of sight of governments. On the other hand, governments are monitoring these flows.
More specifically, they are monitoring Bitcoin revenue streams.
This is a weak argument. When there is no other reason to ban something we start to create fears about it so that people avoid.
I do not know what the real ratio is, but more people are speculating than the number who use BTC for dark activities.
. It is not the article's fault that the clear contradiction is the 2 Chinese individuals who want private transactions but used bitcoin hehehe.