Hi David.
   I visited silk road when it was running.
   It didn't sell assassination.  Ulrich had a policy against this.
   It mostly wasn't about drugs.  Drugs were one of many product
   categories it provided.  It was mostly normal things, to support the
   use of bitcoin.
   A significant portion of drug purchases appeared to be marijuana, which
   is now legal in many states.
   People on the site also sold hard drugs, and services for anonymously
   transferring mail deliveries to people.
   It is not illegal to provide a marketplace.  It seems to me the portal
   provided an avenue for hunting down anyone selling these drugs, because
   they were using the normal postal service to do so.
   I expect that Ulbricht is serving a sentence far in excess of their
   crime, because the site was competing with existing criminal
   marketplaces, and refused to play their game.
   If Ulbricht had real ties to the real black market, clients and
   partners would have protected the site from being taken down, like
   apparently happens in other situations.