You do ask how people ran their drug-and-weapons enterprises before bitcoin. You'd guess it was through shady lawyers, corrupt banks, tax oases and webs of mailbox holding companies all the way down. That's proven working. But with bitcoin you are stuck with the dozen shady exchanges. Any normal criminal would think it's too risky.

>>How big a market is that?

The Black market in countries like India is large enough beyond our comprehension. Large enough that its mixed so well into everyday life, taking action on it could cause massive economic distress.

Bitcoin is the next step in the game for these kind of things. Its like a dream come true.

You jest, but go read bitcointalk.org's archives from a few years ago (and before) and I think you'll find that's exactly the purpose it seems expected to fulfill.