Eleven people, including one of the top spammers in the world, were indicted on Thursday for allegedly sending millions of unsolicited e-mails intended to inflate the price of Chinese penny stocks.

The U.S. Department of Justice (DOJ) called the scheme one of the largest spamming and fraud operations in the U.S. The 41-count indictment charges the defendants with conspiracy, several types of fraud, and money laundering.

The indictment alleges the group sent spam via botnets, or networks of hacked computers. A three-year investigation revealed the e-mails, which implored investors to buy cheap stocks, contained fake headers and other misleading information, the DOJ said.

After the price of a stock increased, the defendants sold at the artificially inflated price, a practice known as a pump-and-dump scam, according to the indictment. In mid-2005, the stock spam netted the defendants around $3 million, the DOJ said.

Those charged include Alan M. Ralsky, 52, of West Bloomfield, Michigan. Spamhaus, a London-based organization that tracks spamming operations, listed Ralsky as one of the top professional spammers in the world. Also indicted was Ralsky's son-in-law, Scott K. Bradley, 46.

Ralsky settled with Verizon after being sued in 2002 over spam. Ralsky and his company, Additional Benefits, agreed to pay Verizon and to stop sending spam on Verizon's network.

Three of the 11 accused have been detained, and the rest -- including Ralsky -- are being sought, the DOJ said.

The IDG News Service is a Network World affiliate.