The Metropolitan Police has arrested a 19 year-old man they believe to be a LulzSec and Anonymous hacker known as 'Topiary'.
Scotland Yard's Police Central e-crime Unit (PCeU) said that the teenager was apprehended at a house in the Shetland Islands and is to be brought to London.
Police are also searching a home in Lincolnshire and questioning a 17 year-old male, although no further arrests have been made.
The PCeU said that 'Topiary' has served as a spokesperson for the hacking groups, which have eschewed any traditional leadership roles or titles for their members.
A single tweet to the @atopiary feed attributed to the hacker reads: "You cannot arrest an idea." All other tweets on the feed appear to have been deleted.
LulzSec and Anonymous offered no specific comment on the arrest on their respective Twitter feeds.
The arrest is the latest in an ongoing international police operation targeting members of the hacking groups. Arrests have also been made on suspected members in the US, Italy, the Netherlands, Spain and Turkey.
Anonymous and LulzSec, meanwhile, have been extremely active in recent days. After suffering a denial-of-service attack on Tuesday, the group introduced a publicity campaign aimed at triggering a mass user exodus from payment service PayPal.
After firing off writs against AMD and Intel, ambulance-chasing lawyers take aim at Apple
Scientists claim to have found a way to create lighter and more reliable batteries
A malicious script has been in operation since November
Scientists are crowdsourcing help in detecting rare high-energy cosmic rays - and all you need is a mobile phone