SEATTLE (AP) — A jury has convicted a Russian man of hacking into U.S. businesses to steal credit card information and orchestrating an international online theft scheme that netted him millions of dollars.

Roman Seleznev could face up to 40 years in prison for stealing millions of credit card numbers that he sold on underground internet forums.

Prosecutors say the thefts led to almost $170 million in losses around the world and made him “one of the most prolific credit card traffickers in history.”

After the verdict Thursday Seleznev’s lawyer, John Henry Browne, vowed to appeal.