If our popular culture is to be believed, most people assume there's a place online where the worst of the headlines you read about drugs, money laundering, murder for hire, and vast child pornography rings are born. It's called many things, though "Dark Web" is the most dramatic.
Although it's true that this Dark Web exists, it's much larger and more diverse than merely these illegal activities. What's more, the same technology that makes it possible for such marketplaces to operate in secret is also protecting political dissidents overseas and hiding everyday Internet traffic from surveillance. It may be that this digital back alley is the path toward a more secure Internet.