To clear a common misconception: BTC is not anonymous. The world knows where you got your coin, and where you spent it; it's there in the journal for all to see. It might not be tied to your name and social specifically, but if you want to give or get goods or services, you'll be interfacing with meatspace at some point and then it will all be tied to you.

So no, BTC is not much good for illicit goods.