WASHINGTON (AP) -- President Donald Trump announced Tuesday that he had pardoned Ross Ulbricht, the founder of Silk Road, an underground website for selling drugs.

Ulbricht had been sentenced to life in prison in 2015 after a high-profile prosecution that highlighted the role of the internet in illegal markets.

Trump posted on Truth Social, his social media website, that he had spoken to Ulbricht's mother on his first full day in office.

"It was my pleasure to have just signed a full and unconditional pardon of her son, Ross," he wrote. "The scum that worked to convict him were some of the same lunatics who were involved in the modern day weaponization of government against me."

Trump called Ulbricht's prison sentence "ridiculous."

He had promised to help Ulbricht during a speech at the Libertarian Party National Convention last May.

Libertarian activists, who generally oppose criminal drug policies, have long believed that government investigators overreached in building their case against Silk Road. Many held "Free Ross" signs.

"Ross Ulbricht has been a libertarian political prisoner for more than a decade," said a statement from Libertarian National Committee Chair Angela McArdle. "I'm proud to say that saving his life has been one of our top priorities and that has finally paid off."

Trump has been eagerly using his pardon power since beginning his second term. On Monday, hours after taking office, he wiped clean the records of roughly 1,500 people who participated in the Jan. 6, 2021, riot at the U.S. Capitol. The decision, which applied to some people who were convicted of attacking police, upended the Justice Department's sweeping investigation into the attack.