Ulbricht was sentenced to life in prison around 4 p.m. Eastern time, according to a spokeswoman for the U.S. Attorney's Office in Manhattan. His defense attorney, Joshua Dratel, was not immediately available for comment.
Ulbricht, who was known to federal agents by his online alias "Dread Pirate Roberts," was convicted in February for allowing more than $180 million in drug deals to take place on
Ulbricht's attorneys have long argued that the 29-year-old California native was framed by other Web-based dealers who were able to conceal their identities.
A Manhattan jury, however, was not swayed by that argument. Ulbricht was convicted after only three hours of deliberations in federal court in New York in February.
In a statement released Friday afternoon, Manhattan's U.S. Attorney Preet Bharara repeated the assertion made at trial that drugs sold on Ulbricht's website contributed to several overdose deaths.
"Make no mistake: Ulbricht was a drug dealer and criminal profiteer who exploited people's addictions and contributed to the deaths of at least six young people," Bharara said. "Ulbricht went from hiding his cybercrime identity to becoming the face of cybercrime and as today's sentence proves, no one is above the law."
Silk Road surfaced in 2010, and federal agents began infiltrating the site one year later. Homeland Security Agent Jared Der-Yeghiayan, who was first tipped off to the site's existence during a 2011 drug bust in Chicago, began posing as a Silk Road member. He climbed the website's ranks by taking over staff member accounts each time federal agents made an arrest or convinced a suspect to cooperate with the investigation.
The government presented numerous instant messages at Ulbricht's trial between Der-Yeghiayan and Ulbricht.
While Ulbricht's attorney has claimed his client quit the website once it was overrun by drug dealers, federal prosecutors have also charged Ulbricht with plotting the deaths of at least five people he saw as threats to Silk Road. Ulbricht is awaiting a murder-for-hire trial in Baltimore.
The Silk Road investigation also led to criminal charges against two former federal agents who were involved in the investigation: Carl M. Force, a former investigator with the Drug Enforcement Administration, repeatedly asked Ulbricht to pay him for information on the federal investigation into Silk Road, prosecutors have said.
Shaun W. Bridges, a former Secret Service member, has also been charged with stealing hundreds of thousands of dollars in digital currency from the website while investigating the drug dealing on Silk Road.