In a simultaneous crackdown across Spain, police have claimed to have arrested three people who they believe form the core group of the online hacktivist group Anonymous in Spain.
The Spanish national police force had begun an investigation into the hackitivist group's network in October 2010. After scanning millions of lines of chat logs, authorities manged to infiltrate the group.
The arrests took place simultaneously in Barcelona, Valencia and Almeria. Police said they have also seized a computer that was used in for hacking. It is believed that a Web-based tool 'Loic' used by the hackers for the Distributed Denial of Service (DDoS) attacks allowed authorities to track down the hackers.
Prior to the arrests in Spain, Anonymous members have been arrested in other countries including the US, the UK and Holland.
The crackdown follows the recent surge in cyber attacks.
Recently, hacker group Lulz Security (LulzSec) breached into the servers of PBS and IfraGard, an affiliate of the FBI. Anonymous is believed to be behind the massive data breach of Sony's PlayStation Network (PSN) that took place in April.
In the past, Anonymous had brought down websites of of PayPal, Mastercard and Amazon in defence of whistle-blowing site Wikileaks. It is believed that Anonymous is also behind the major cyber attack on the International Monetary Fund (IMF) that took place on Saturday.
In response to the crackdown in Spain, Anonymous denied the police claim that they had arrested a core group.
In a report in El Mundo, Anonymous said, "They did not arrest any core group ... because we don't have a core group."
The newspaper also reported that the group had brought down the website of Spain's national police force for over an hour on Saturday as a retaliation.
A spokesman for the police has confirmed the outage but said that the cause has yet to be confirmed.
"A website can collapse if too many people try to access it at once. I cannot confirm the link with the Anonymous group," the spokesman said.