York student Glenn Mangham admits Facebook hack
A software development student hacked into Facebook with "considerable expertise", a court heard.
Glenn Mangham, 26, admitted hacking into the social networking site between April and May, when he appeared at Southwark Crown Court.
The action caused American authorities to fear an industrial espionage attack.
Mangham, of Cornlands Road, York, had shown the search engine Yahoo how to improve its security and wanted to do it for Facebook, the court heard.
'Most effective hacking'
Prosecutor Sandip Patel said the defendant's actions caused concern among a number of American authorities including the FBI.
Mangham's actions were the "most effective and egregious example of hacking into social media that has come before a British court", he told the court.
Mangham downloaded his own computer programmes on to Facebook's servers and saved "highly sensitive intellectual property" on to an external drive so he could work on it off line.
"It required considerable expertise," said Mr Patel.
In a statement to BBC News, Facebook said: "This attack did not involve an attempt to compromise or access user data."
Facebook discovered the infiltration during a system check even though the defendant deleted his electronic footprint to cover his tracks, the prosecutor said.
Mr Mangham's defence lawyer Tom Ventham said his client was an ethical hacker who had a "high moral stance" and Yahoo had "rewarded" him for pointing out its vulnerabilities previously.
"That was his plan here but the activity was found by accident," said Mr Ventham.
He added that when Mangham was arrested he made a "copious" admission to police about what he had done.
Mangham will be sentenced on 17 February.