He was unique in his magnitude of success. Governments can successfully magnify their enforcement ability by making an example of outliers.
I find that hard to believe.
Here's the thing about the US federal law enforcement: there aren't actually a lot of them. In a country of 380 million people, there are 38,000 agents. Google employs more people than the FBI. If the US citizenry decided to take collective action against them, the federal domestic police force alone could not stand against the citizenry.
This shapes where they apply their resources. To be most effective, they need to be visible so that people don't start to think of them as toothless, because mass-resistance to their general police activities would actually work. So they pursue cases into the dust to generate high-profile images of lawbreakers having a really awful time to discourage other lawbreakers.
He was prosecuted because he broke US drug law. But he was prosecuted to the extent he was prosecuted because Silk Road had made headlines as something untouchable by federal authority. That's the kind of Capone energy that the federal law enforcement cannot abide and survive as an institution.
Inconceivable!