The Federal Bureau of Investigation has arrested 14 members of hacking group Anonymous for their alleged involvement in a cyber attack on PayPal's Web site.

The arrests were part of a nationwide raid that took place in Alabama, Arizona, California, Colorado, the District of Columbia, Florida, Massachusetts, Nevada, New Mexico and Ohio.

The defendants are charged for allegedly conspiring with others to intentionally damage protected computers at PayPal from Dec. 6 to 10, 2010.

The charge of intentional damage to a protected computer carries a maximum penalty of 10 years in prison and a $250,000 fine. Each count of conspiracy carries a maximum penalty of five years in prison and a $250,000 fine.

PayPal, which allows payments and money transfers to be made via the Internet, was attacked in December 2010 in a series of distributed denial-of-service (DDoS) attacks organized by Anonymous.The attacks were executed in retaliation for PayPal's decision to freeze the account of WikiLeaks citing terms of use violations over the publication of leaked U.S. diplomatic cables.

Anonymous referred the DDoS attacks on PayPal as Operation Avenge Assange.

DDoS attack occurs when multiple systems flood the bandwidth or resources of a targeted system, usually one or more Web servers. These systems are compromised by attackers using a variety of methods.

In other words, DDoS attacks are attempts to render computers unavailable to users through a variety of means, including saturating the target computers or networks with external communications requests, thereby denying service to legitimate users.

In April 2011, 'Anonymous' launched an attack on the media giant Sony, as part of the Operation Payback, after Sony took legal action against George Hotz, the coder behind a popular tool that allows homebrew software to run on the PlayStation 3 (PS3).

In December 2010, 'Anonymous' announced its support for WikiLeaks after the whistle-blowing website came under intense pressure to stop publishing secret United States diplomatic cables.

Following that, 'Anonymous' launched DDoS attacks against Amazon, PayPal, MasterCard, Visa and the Swiss Bank PostFinance, in retaliation for perceived anti-WikiLeaks behavior.

Due to the attacks, both MasterCard and Visa's websites were brought down on December 8.

Other Arrests

FBI, which arrested two others on cyber-related charges, executed more than 35 search warrants throughout the United States as part of an ongoing probe into coordinated cyber attacks against major companies and organizations.

To date, more than 75 searches have taken place in the United States as part of the ongoing investigations into these attacks.

FBI also arrested Lance Moore, 21, of Las Cruces, New Mexico, for allegedly stealing confidential business information stored on AT&T's servers and posting it on a public file sharing site.

According to the New Jersey complaint, Moore, a customer support contractor, exceeded his authorized access to AT&T's servers and downloaded thousands of documents, applications and other files that, on the same day, he allegedly posted on a public file-hosting site that promises user anonymity.

On June 25, the computer hacking group LulzSec publicized the same confidential AT&T documents and made them publicly available on the Internet.

Separately, the United Kingdom's Metropolitan Police Service arrested one person and the Dutch National Police Agency arrested four individuals for related cyber crimes.

Following are the members of 'Anonymous' arrested by FBI:

Christopher Wayne Cooper, 23, aka Anthrophobic

Joshua John Covelli, 26, aka Absolem and Toxic

Keith Wilson Downey, 26

Mercedes Renee Haefer, 20, aka No and MMMM

Donald Husband, 29, aka Ananon

Vincent Charles Kershaw, 27, aka Trivette, Triv and Reaper

Ethan Miles, 33

James Murphy, 36

Drew Alan Phillips, 26, aka Drew010

Jeffrey Puglisi, 28, aka Jeffer, Jefferp and Ji

Daniel Sullivan, 22

Tracy Ann Valenzuela, 42

Christopher Quang Vo, 22

One individual's name has been withheld by the court, FBI said in a statement.