A U.S. jury on Thursday indicted 13 members of a loose-knit Internet hacking group for allegedly carrying out cyber-attacks worldwide, including targets that refused to process payments for WikiLeaks, the anti-secrecy website founded by Julian Assange.

The U.S.-based members of Anonymous are accused of zeroing in on the computers of governments, trade associations, law firms, financial institutions and other institutions that oppose the philosophy of Anonymous to make all information free for everyone, regardless of copyright laws or national security considerations.

The indictment filed in federal court says that from September 2010 to January 2011, Anonymous members participated in a campaign they called Operation Payback, using software known as the Low Orbit Ion Cannon to flood websites with huge amounts of Internet traffic to shut them down.

In December 2010, the conspirators discussed possible targets related to WikiLeaks, which received more than 700,000 documents and some battlefield video from Army Pvt. Chelsea Manning, the largest-volume leak of classified material in U.S. history.

Anonymous focused on websites that were either critical of WikiLeaks or had refused to process payments for WikiLeaks, among them MasterCard and Visa. The targets even included the Swedish prosecutor’s office, in connection with arrest warrants for sexual crimes issued for Assange.

Members of Anonymous launched what they called Operation Payback, an attack on the Motion Picture Industry of America, the Recording Industry Association of America, the British Phonographic Industry and others. The attacks were retaliation against the discontinuation of “The Pirate Bay,” a Sweden-based file sharing website devoted to the illegal downloading of copyrighted material.

They used what are known as denial-of-service attacks to overwhelm websites and make them inaccessible.

In March 2012, U.S. prosecutors in New York charged six suspected leaders of Anonymous for wreaking havoc on government and corporate websites.

According to the indictment, Anonymous then moved against others such as Bank of America Corp, ACS:Law, a British law firm helping clients to protect intellectual property rights; Anti-piracy.nl, the website for the BREIN foundation, a Dutch trade association fighting intellectual property theft; and the Australian Federation Against Copyright Theft.

The website of the U.S. Copyright Office at the Library of Congress has been the subject of multiple recent cyber attacks.

Those charged ranged in age from 21 to 65 and lived in 13 different U.S. states.