A teenager who tricked his way into obtaining the email and phone accounts of senior US intelligence officials has been sentenced.
Kane Gamble, 18, targeted CIA, FBI and US Department of Justice databases from his bedroom in Leicestershire.
The Old Bailey was told Gamble, who has admitted a number of charges, damaged the "effectiveness" of the wider law enforcement community.
He will serve two years at a youth detention centre.
His defence said he was "naive" and never meant to "harm" any individuals.
But the judge, Mr Justice Haddon-Cave said Gamble ran a "campaign of cyber terrorism".
Gamble obtained "extremely sensitive" documents on military and intelligence operations in Iraq and Afghanistan, the court was told.
Between June 2015 and February 2016, he targeted the former CIA chief John Brennan and FBI deputy director Mark Giuliano from his home in Linford Crescent, Coalville.
The judge was told he impersonated his victims and conned call centres into divulging confidential information.
He then sent emails from agents' accounts and accessed sensitive military information.
Gamble also leaked some of the information he gathered using various websites including WikiLeaks.
The court was told Gamble uploaded details of 20,000 FBI employees obtained from the US Department of Justice, with the message "This is for Palestine".
He bragged "this is so serious I'm shaking" and "this has to be the biggest hack ever".
He even managed to use the TV in the house of then US Secretary of Homeland Security Jeh Johnson to post the message "I own you".
The teenager also left a disturbing voicemail message for Mr Johnson's wife, Susan DiMarco asking "hi spooky, am I scaring you?".
Gamble - the founder of hacking group, Crackas With Attitude (CWA) - pleaded guilty in October to 10 charges.
Prosecutor, John Lloyd-Jones QC highlighted the level of sophistication and persistence in the attacks, as well as the damage caused.
Defending, William Harbage QC said Gamble, who is on the autistic spectrum, was "naive" and "childish" and his actions were a response to what he had read about in online chat rooms about US policy.
Mr Harbage said the teen thought he could get them to change "as a result of what he was doing from his bedroom".
Mr Harbage had argued for a suspended sentence, saying Gamble was due to sit GCSEs in June and hoped to read computer studies at university and pursue a "useful" career.
Gamble made no reaction as he was sentenced but his mother wept in the well of the court.
Judge Haddon-Cave ordered the seizure of his computers.