US authorities say they have busted an online black market for drugs, hitmen, hacker tools and more, arresting the suspected mastermind of a nefarious bazaar called Silk Road.

Federal agents shut down the website, which used a privacy-protecting Tor network and Bitcoin digital currency to shield the identities of buyers and sellers around the world.

Ross William Ulbricht, also known as ‘‘Dread Pirate Roberts’’, was arrested in San Francisco after the website was shut down, the Justice Department said in a statement on Wednesday.

His online moniker appeared to be taken from a character in the film The Princess Bride.Prosecutors said they seized approximately $3.6 million worth of Bitcoins in the largest ever seizure of the digital currency.

‘‘The Silk Road website has served as a sprawling black market bazaar where illegal drugs and other illicit goods and services have been regularly bought and sold by the site’s users,’’ FBI Special Agent Christopher Tarbell said in a criminal complaint filed in federal court.