A 21-year-old California resident was arrested on charges that he attacked the Web sites of two businesses using a botnet made up of about 7,000 computers, the U.S. Attorney's Office for the Eastern District of California stated on Monday.

An indictment released last week, but kept under seal until the arrest, charged Greg King of Fairfield, Calif., with four counts of electronic transmission of code to cause damage to protected computers. King allegedly identified himself as "Silenz", "sZ," and "GregK" online, according to the indictment.

"When agents went to arrest King at his residence (on Monday) morning, King went out the back door of the residence carrying a laptop computer, depositing it in the bushes in the backyard," the U.S. Attorney's said in a statement (PDF). "Agents obtained a warrant to search King's backyard and seized the computer."

Investigations by both the FBI and the U.S. Secret Service have led to the arrests of suspected cybercriminals this year. In March, Florida officials linked a ring of alleged gift-card fraudsters with credit-card accounts stolen from retail giant TJX Companies. Secret Service investigations led to suspected members of an international credit-card counterfeiting ring, while U.S. prosecutors arrested a former security professional on charges of ID theft.

The charges against King stem from attacks on an online forum known as Killanet and against anti-fraud site CastleCops. King, if found guilty of the charges, could face a maximum sentence of 10 years in prison and a $250,000 fine.