Yes sure it had wide use in illegal activities because it's anonymous and gives criminal freedom of money and they keeps themself hidden.
of course when the criminals have a more secure method to transact course they will use it, and bitcoin easier for them and make them become more invisible, they would use bitcoin
It definitely help them in their job to transact illegal activities but do we really care for that? It's not our business to mind them, let the government do their duty but to us we just keep ourselves updated any possible ways to create demand will surely be an opportunity we have to wait the outcome.