A 28-year-old Bulgarian man, nicknamed The Hacker, was jailed for 4-1/2 years on Monday for draining over a million dollars from bank cards, mostly owned by U.S. citizens.

A court in the Black Sea city of Varna convicted the man after he pleaded guilty to charges of founding an organised crime group for money laundering, financial fraud and extortion. Four members of his gang had received varying sentences, the worst being for 1-1/2 years and a 5,000 lev fine.

"Issa Mehmed, nicknamed 'The Hacker' ... has carried out dozens of financial operations, linked with draining bank cards, mainly owned by U.S. citizens in different U.S. banks," the court said in a statement.

The District Court of Varna said the crimes were conducted from June 2003 until January 2008, when the gang was arrested.

The sentence meant "The Hacker" would have to pay back the stolen funds worth 1.787 million levs ($1.19 million) and pay a fine of 5,000 levs.

The European Union newcomer has vowed to step up its fight against organised crime and corruption to avoid sanctions from Brussels, which has frozen 220 million euros ($284.3 million) in aid because of slow reforms and financial fraud.