The attack on the bank was one of the defining images of the protests
A student from Brighton who took part in an attack on a bank during the G20 protests in central London has been jailed for two-and-a-half years.
Phillip Georgopoulos, 26, helped throw a computer monitor through the window of the Royal Bank of Scotland's Threadneedle Street branch in the City.
He went on to launch a piece of metal the size of a house brick at police as the protests continued on 1 April 2009.
The fine arts student admitted violent assault at Isleworth Crown Court.
The vandalism of the bank was one of the defining images of the anti-capitalist protests.
CCTV cameras captured Georgopoulos, who holds joint Greek and American nationality, taking part in the attack.
He was trapped outside the Royal Bank of Scotland by police who had contained demonstrators using the controversial "kettle" technique, the court heard.
Later the student dragged metal barriers towards a line of police and threw the metal clip - used to connect the barriers - at the police.
No-one was injured, prosecutor Ravinder Johal said.
Mitigating, Richard Parry said his client suffered from attention deficit disorder and dyspraxia and got "easily caught up in situations".
"This was an unfortunate incident that arose spontaneously while a crowd was corralled by police, with effectively nowhere to go."
Sentencing Georgopoulos, Judge Georgina Kent said: "It was a major incident of violent disorder and no doubt others were encouraged by your behaviour."
Georgopoulos, of Prestonville Road, had a previous conviction for causing criminal damage and common assault.