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.
With £6.7m in initial funding, Mosa Meat could be the first company to offer lab-grown meat to the public
Manufacturing and finance jobs will be hit, but health and education can look forward to job creation, says PwC
US startups plan to modify existing jet engines, but are likely to fall foul of environmental legislation
The Brexit white paper "gets pretty close" to company desires, but there's still work to do