A federal judge sentenced the mastermind behind online drug marketplace Silk Road, Ross Ulbricht, to life in prison Friday.

“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," Manhattan U.S. Attorney Preet Bharara said in a statement.  "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.”

Ulbricht was convicted on seven counts, including conspiracy and money laundering, in February for operating an online bazaar where users bought drugs and other illegal goods. He faced a minimum of 20 years in prison.

His defense team argued that Ulbricht didn't create the site for financial gain, and submitted nearly 100 letters from family, friends, and supporters testifying to his character.

"I’ve had my youth, and I know you must take away my middle years, but please leave me my old age," Ulbricht wrote in a pre-sentencing statement. "Please leave a small light at the end of the tunnel, an excuse to stay healthy, an excuse to dream of better days ahead, and a chance to redeem myself in the free world before I meet my maker."

But prosecutors had argued that Ulbricht, who was known online by the Princess Bride-based pseudonym "Dread Pirate Roberts," deserved a stiff sentence because he bears some responsibility for the drug overdoses and other damage done to the public by drugs sold on the Silk Road.

U.S. District Judge Katherine B. Forrest in New York rejected Ulbricht's pleas for leniency. “It was a carefully planned life’s work,” Forrest said at the sentencing hearing. “It was your opus.”

Silk Road, which operated in what’s known as the Dark Web because it’s not easily accessible to all Internet users, became a notorious marketplace for illegal goods for three years before being closed down in 2013. Transactions were made in Bitcoins, a digital currency that helped shield their identity.