A Ukrainian man extradited from Italy has gone on trial in New Jersey accused of running a botnet and dealing in stolen credit cards.

"Vovnenko commandeered thousands of computers to create a virtual army of hacked computers that he and his conspirators used to break into other networks and steal valuable information," US Attorney Paul Fishman alleged on Tuesday.

"Thanks to the work of our law enforcement partners here and in Italy, he is now in America to answer for his alleged crimes."

Sergei Vovnenko, aka "Fly," "Centurion," and "Darklife," has been sought by the authorities for some time after being fingered as a prime mover in the black hat hacking movement. He is accused of running several underground malware markets and offering his 13,000-strong botnet for hire.

The indictment claims that between September 2010 and August 2012, Vovnenko and his associates conducted a hacking campaign to build a botnet and harvest financial and identity information to be sold online.

Vovnenko was picked up by Italian police last summer after a joint operation with American police. He spent 15 months fighting extradition to the US but failed, and the trial started on Tuesday.

One person likely to be taking a keen interest in the proceedings is investigative blogger Brian Krebs, who Vovnenko appears to have taken a strong dislike to. Krebs alleges that the Ukrainian harassed him and his wife with threatening notes and sent them heroin to try and shut the journalist up.

Krebs, who lives in Northern Virginia, US, was monitoring a number of message boards that Vovnenko frequented. The blogger spotted a discussion between hackers where participants were discussing a plan to buy heroin on Silk Road, send it to Krebs, and then tip off the police. Krebs was able to warn the police of the plot, and track the drugs shipment via a UPS number posted on the forum.

Those events don't form the basis for any of the current charges against Vovnenko, but he has enough problems as it is. He's been charged with wire fraud, unauthorized computer access, and four counts of identity theft, which could put him away for 43 years. ®