Police have arrested a 17-year-old suspected spokesman for Team Poison, a hacking group that has claimed responsibility for a series of high-profile cyber-attacks.
The boy was arrested on Wednesday in Newcastle in connection with alleged computer misuse offences, London's Metropolitan Police said.
"The suspect, who is believed to use the online 'nic' (nickname) 'MLT', is allegedly a member of and spokesperson for TeaMp0isoN ('TeamPoison')," Scotland Yard said in a statement.
"He has been taken to a local police station for interview. Computer equipment has been seized and is undergoing a detailed forensic examination."
Team Poison, believed to be behind cyber-attacks on Facebook founder Mark Zuckerberg and the Facebook page of outgoing French President Nicolas Sarkozy, "has claimed responsibility for more than 1,400 offences", the statement added.
These offences include "denial of service and network intrusions where personal and private information has been illegally extracted from victims in the UK and around the world," police said.
Scotland Yard itself came under attack from Team Poison last month, when the group uploaded a four-minute recording of conversations between staff manning Britain's confidential anti-terrorist hotline to YouTube.
Police admitted the recordings were genuine, but insisted they were not obtained through hacking and that their internal communication systems were secure.