The man accused of masterminding the Silk Road black market drug website was actually set up by the mysterious "Dread Pirate Roberts" in whose name the site was run, the defense said Tuesday in an unexpected opening argument in federal court in Manhattan.

Defense lawyer Josh Dratel told jurors that Ross Ulbricht, who prosecutors say used the pseudonym to run a sprawling online drug bazaar, had founded the site as an "economic experiment" but turned it over to others who corrupted it and then cleverly framed him.

"Ross was the perfect fall guy," Dratel said. "They left him holding the bag when the real operators knew their time was up."

Ulbricht, 30, of San Francisco, faces up to life in prison on multiple conspiracy charges for allegedly using an encrypted corner of the Internet and digital bitcoin currency to construct a website that hosted thousands of drug dealers and buyers under a cloak of anonymity to thwart law enforcement.

The government says that hiding behind the online identity "Dread Pirate Roberts" -- a character in the film "The Princess Bride" -- Ulbricht used his programming skills to create Silk Road and took a commission on every drug deal, amassing $18 million in bitcoin between 2011 and 2013 from a global network of users.

"Like a traditional drug boss, he made it all possible," prosecutor Tim Howard said. " . . . The defendant's territory wasn't a city block or a neighborhood -- it was the entire world, and he controlled everything from behind his computer."

Since his 2013 arrest, Ulbricht's lawyers, family and a cadre of libertarian supporters have cast the case as a test of Internet freedom, challenging law enforcement tactics used to penetrate Silk Road's anonymity and to charge him for merely hosting a site on which others sold drugs.

Ulbricht has never conceded that he was "Dread Pirate Roberts." Tuesday, the boyish-looking defendant -- outfitted in a preppy blue blazer and white khakis -- shook his head each time Howard claimed it was him.

Prosecutors say agents arrested Ulbricht in a public library communicating as "Dread Pirate Roberts" with an undercover agent. He was using a laptop, they say, that was logged in to Silk Road's private "Mastermind" administrator's page as "Dread Pirate Roberts."

But Dratel said Ulbricht founded Silk Road as a "freewheeling" marketplace, but turned it over to others when it became "too stressful." Those individuals allowed drugs to flourish under the name "Dread Pirate Roberts" and then lured Ulbricht back as investigators closed in.

"Ross Ulbricht," he argued, "ultimately became the victim of Dread Pirate Roberts."