The FBI has arrested Oleg Nikolaenko, who is allegedly behind the Mega-D botnet, which at one point accounted for nearly a third of all of the spam on the Internet. He was arrested in Las Vegas in early November while attending a car show, and was carrying $4,000 in cash. Nikolaenko worked with affiliates in several countries around the world to push products through spam, including fake watches and herbal supplements, according to JSOnline.

An affidavit filed by the FBI in the US District Court in Wisconsin says agents got onto Nikolaenko's trail after one of his alleged associates, an Australian man named Lance Atkinson, agreed to plead guilty and eventually began telling authorities about his dealings with others in the underground. He filled them in on a spam and affiliate marketing scam that Nikolaenko (whom he called Docent) was involved in.

The FBI worked with the FTC and others to investigate and shutdown a large spamming operation known as Affking. "In the interview, Atkinson explained his involvement in the Affking and related enterprises, including Affking predecessor companies Genbucks and Sancash," FBI agent Brent Banner wrote in his complaint against Nikolaenko. "Specifically, he recalled that two of his largest Russian spamming affiliate used the online monikers 'Docent' and 'Dem'."

The FBI eventually got access to e-mail accounts involved in the payment chain of the affiliate marketing program via a federal subpoena. One of them belonged to Nikolaenko and a search warrant gave them access to the e-mails themselves, as well as a conversation between Nikolaenko and Atkinson, in which the two discussed spam operations. The FBI also found e-mails which contained the executable file for the Mega-D malware. When the botnet was taken down, Banner says in his complaint that Nikolaenko was in the US but left the country two days early, likely to go home and fix the damage.

Nikolaenko is being held in Wisconsin; he could face up to three years in prison and a $250,000 fine if convicted. The Russian has pleaded not guilt, according to Reuters.