The self-proclaimed leader of hacking group LulzSec has been arrested in Australia.
An as-yet unnamed 24-year-old senior IT worker was detained on Tuesday night at his office in Sydney.
The man is accused of hacking into and defacing an Australian government website earlier this month.
He was charged with two counts of unauthorised modification of data to cause impairmen, and one count of unauthorised access to, or modification of, restricted data.
These charges carry maximum sentences of 10 and two years respectively.
Anonymous Australia denied the man arrested was LulzSec's leader calling the man's claim "absolute bull****".
A statement from the Australian police said: "Those thinking of engaging in such activities should be warned that hacking, creating or propagating malicious viruses or participating in Distributed Denial of Service attacks are not harmless fun.
"Criminal acts such as this can result in serious long-term consequences for individuals, such as criminal convictions or imprisonment."
The LulzSec group have been responsible for a number of high profile attacks after members of Anonymous broke away to form the collective.
They gained worldwide notoriety in 2011 after hacking into the accounts of millions of Sony user accounts via the company's website.
The attack is thought to have cost Sony £65 million.
LulzSec have also targeted Fox.com, the CIA and the UK Serious Organised Crime Agency.
A British member of the group, Ryan Ackroyd, pleaded guilty this month to hacking the NHS, Sony and News International.
The 26-year-old is awaiting sentencing.
Another, Ryan Cleary who was diagnosed with Asperger's Syndrome, was the subject of a failed extradition attempt to the US to face charges of creating a malicious botnet.
The group's name is derived from "Lulz", internet slang that can be interpreted as "laughs" and "sec", short for security.
Their slogan is "Laughing at your security since 2011".