I remember that a few years ago, bitcoin was related to the dark web and the black market that could be found there, where you could buy many illegal things or hire a hitman.
At present, I believe that part of those ideas of absolute anonymity with the use of bitcoin remains in the general population, but the facts repeatedly show that the flow of payment operations in the blockchain and the laundering of criminal capital can be identified.
This case of the pedophile network is one more that shows that the destination of payments and purchases can be traced within the illegal markets and is accepted evidence in the investigation processes in different countries.