Scotland Yard on Wednesday arrested a hacker known as "Topiary" for his alleged involvement in the activities of Anonymous and LulzSec.
The 18-year-old was arrested in the Shetland Islands and is currently being transported to a central London police station, the Metropolitan Police said in a statement.
"The man arrested is believed to be linked to an ongoing international investigation in to the criminal activity of the so-called 'hacktivist' groups Anonymous and LulzSec, and uses the online nickname 'Topiary' which is presented as the spokesperson for the groups," the police said.
Officials are also searching a house in Lincolnshire and questioning a 17-year-old boy connected to the inquiry, but he has not been arrested, police said.
As PCMag pointed out in a recent overview of the key LulzSec players, Topiary is reportedly second-in-command within LulzSec, though he is thought to be the least tech-savvy in the group. As a result, he acted as a PR liaison for Anonymous before moving over to LulzSec.
He recently deleted posts from the @atopiary Twitter account; it now only has one tweet from July 21: its new "You cannot arrest an idea" tagline. The bio on that Twitter page says Topiary is a "simple prankster turned swank garden hedge [who] worked with Anonymous, LulzSec, and other such paragons of intense cyber victory. You are free."
The @LulzSec Twitter feed has not been updated for seven hours; the last message encouraged people to join in the Anonymous-led effort against PayPal.
As Sophos analyst Graham Cluley pointed out in a blog post, "LulzSec and other hacktivist groups have recently been playing an extremely dangerous game—taunting the likes of the FBI and British police with a series of hacks and attacks and believing themselves to be invincible."
Last week, Scotland Yard also arrested a 16-year-old boy for suspected violations of the country's Computer Misuse Act. He reportedly used the Internet name TFlow, which has links to LulzSec. That arrest was in conjunction with 16 hacker arrests in the U.S. as well as four in the Netherlands.
Not surprisingly, the arrests did not sit well with Anonymous. The group said today that it was "outraged" by the recent arrests. "Anonymous 'suspects' may face a fine of up to 500,000 USD with the addition of 15 years' jailtime, all for taking part in a historical activist movement," Anonymous said. "What the FBI needs to learn is that there is a vast difference between adding one's voice to a chorus and digital sit-in with Low Orbit Ion Cannon, and controlling a large botnet of infected computers. And yet both of these are punishable with exactly the same fine and sentence."
Editor's Note: This story was updated Thursday after Scotland Yard changed the man's age from 19 to 18.