A San Francisco man who launched an underground website as an economic experiment before abandoning it was fooled into taking the fall when investigators concluded it was used almost solely for drug dealing, a defense lawyer told jurors Tuesday after the government portrayed his client as the mastermind of a worldwide digital drug market.

Ross William Ulbricht was “left holding the bag” by operators of the Silk Road website after they were alerted that federal investigators were closing in, defense attorney Joshua Dratel said in his opening statement at Ulbricht’s criminal trial.