The teen Kane Gamble accessed highly senstive information and harassed American officials from his mother's home in England. The court said he did it due to various injustices committed by the US government.
The British teenager gained access to the accounts of top US intelligence and security officials from his home computer in central England, a UK court heard on Friday.
Kane Gamble, 18, was only 15 and 16 when he was able to impersonate top American officials such as former CIA chief John Brennan in order to gain access to personal accounts and secret government information.
"Kane Gamble gained access to the communications accounts of some very high-ranking US intelligence officials and government employees," prosecutor John Lloyd-Jones told England's Old Bailey central criminal court.
"He also gained access to US law enforcement and intelligence agency networks."
The teenager has admitted to 10 counts of violating the computer misuse act and is awaiting sentencing.
The crimes occurred between June 2015 and February 2016. He was arrested at the FBI's request in February last year in Coalville, central England.
Gamble used an information security tactic known as "social engineering" to manipulate call centers and help desks to gain information, which was then further exploited to gain access to various accounts.
The operation was done with the hacking group "Crackas With Attitude" and some information was shared with Wikileaks or posted on Twitter.
Gamble was able to impersonate Brennan in phone calls with telecommunications giants and in another instance trick the FBI help desk into thinking he was Mark Guiliano, the agency's former deputy director.
The teenager was able to access Brennan's private email and iCloud, take control of his wife's iPad, and get information on sensitive military and intelligence operations in Afghanistan and Iran, the court heard.
'I own you'
Gamble used social engineering tactics to access the home network of former Secretary of Homeland Security Jeh Johnson.
He was able to listen to Johnson's voice messages and harass his wife with messages such as "Am I scaring you?" He also managed to get the message "I own you" on the couple's home television.
Among the other targets were former Obama administration officials, including White House deputy national security adviser Avril Haines, director of national intelligence James Clapper and Vonna Weir Heaton, the executive of the National Geospatial Intelligence Agency.
Gamble also gained access to the US Department of Justice network and court case files, including on the Deepwater oil spill.
Prosecutors said Gamble was motivated by his sympathy with Palestinians and due to the United States "killing innocent civilians."
The court also heard arguments from experts that the young boy didn't understand the significance of what he was doing because of autism.
"I'm very clear that he has an autistic spectrum disorder (ASD)," forensic psychiatrist Dr Steffan Davies told the court. "He spent most of his life in his bedroom on the internet and that is where he is getting his cues from."
"He has a very black and white understanding of what was happening, seeing it more as a video game with goodies and baddies," he said. "He was trying to right what he saw as an injustice."
Another expert, Dr Philip Joseph, said that at most Gamble had mild autism but that didn't explain his actions.
"If he had that condition, it doesn't explain why he committed these offences," he said.
Gamble will be sentenced at a later date.