Fourteen people have been arrested for allegedly mounting a cyber attack on the PayPal website after it suspended the accounts of WikiLeaks.
Separately, FBI agents executed more than 35 search warrants around the country in a continuing investigation into coordinated cyber attacks against major companies and organisations.
As part of the effort, there were two arrests in the United States unrelated to the attack on the PayPal payment service. Outside the US, a 16-year-old boy was arrested by Scotland Yard in south London, and there were four arrests by the Dutch National Police Agency, all for alleged cybercrimes.
In one case unrelated to PayPal and filed in New Jersey, a customer support contractor was charged with stealing confidential business information on AT&T's servers. The data was posted on a public file sharing site, and Lance Moore, 21, of Las Cruces, New Mexico, was accused of exceeding his authorised access to AT&T's servers in downloading thousands of documents and applications.
According to court papers, the documents the contractor uploaded were the same ones publicised last month by the computer hacking group Lulz Security, or LulzSec, which said it had obtained confidential AT&T documents and made them publicly available on the internet.
The 16-year-old detained in London is thought to be connected to LulzSec, according to a UK official familiar with the investigation.
The cyber attacks on online payment service PayPal's website by the group called Anonymous followed the release by WikiLeaks in November of thousands of classified US State Department cables.
Anonymous is a loosely-organised group of hackers sympathetic to WikiLeaks. It has claimed responsibility for attacks against corporate and government websites worldwide. The group also claims credit for disrupting the websites of Visa and MasterCard in December when the credit card companies stopped processing donations to WikiLeaks and its founder Julian Assange.
A federal indictment unsealed in US District Court in San Jose, California, says Anonymous referred to the cyber attacks on PayPal as "Operation Avenge Assange".
The 14 charged in the PayPal attack were arrested in Alabama, Arizona, California, Colorado, the District of Columbia, Florida, Massachusetts, Nevada, New Mexico and Ohio. They were aged between 20 and 42.