An associate of hate preacher Anjem Choudary has been jailed for 28 months for knocking a schoolboy unconscious because he cuddled his girlfriend in the street.
Michael Coe, a Muslim convert, has a long record of violent offences starting when he was 16, including assaults, burglary, robbery and violent disorder.
The married father of two was convicted in August of attacking the boy after he took exception to the 16-year-old cuddling his teenage girlfriend in Newham, east London, in April.
The 35-year-old was radicalised in prison by al Qaida terrorist Dhiren Barot in 2007 while serving an eight-year term for firing a shotgun at police during an arrest.
Sentencing him at Southwark Crown Court, Judge Michael Gledhill QC said: "At the time of these offences you either held extremist views or views that were getting very close to extremist views.
"And I have no doubt at all that these views were nurtured in prison and probably outside prison by your association with convicted extremists in prison, and perhaps out of prison."
He added: "You stopped to reprimand them, and you were acting as a self-appointed enforcer of your interpretation at the time of how Muslims should behave."
The judge said he had concluded this for two reasons. "Firstly, when you told the boy to let the girl go, you asked him how would he feel if someone did the same to his sisters.
"When he protested that he was doing nothing wrong, he showed you his school tie to let you know that he was just a schoolboy.
"You then asked him, and then her, whether they were Muslim. They both denied that they were.
"Why? Because they were frightened of what you would do if they told you the truth, that they were in fact Muslim.
"Denying their religion shows just how threatening you were when they said they were not Muslim."
The judge continued that the second reason he believed Coe was policing how he thought young Muslims should behave is because he was involved in a similar incident in 2013.
He was convicted of religiously aggravated harassment after seeing a Muslim woman talking to a group of men and telling her that it was against Islam.
Coe, also known as Mikaeel Ibrahim, has attended a number of extremist demonstrations, including protests over the banning of niqabs in France and the values of Sharia law.
He became a close associate of convicted hate preacher Choudary, founder of the banned organisation al-Muhajiroun, of which Coe was a member.
Coe was driving through east London when he spotted the two 16-year-olds hugging on the pavement.
He pulled over to confront the pair, demanding to know if they were Muslims, before calling the boy's girlfriend a "whore".
He then grabbed the boy by the throat and threw him to the ground before kicking his head as he lay there, leaving him unconscious and bleeding from two head injuries.
When passing schoolteacher Boutho Siwela tried to come to the teenager's aid, he was also attacked.
Coe, who is 6ft 1in and weighs 16 and a half stone, admitted "shoving" the boy, who is half his size, but claimed he was acting in self defence.
In a victim impact statement the youngster, who cannot be named for legal reasons, said the attack had left him frightened of older men.
Reading from the statement, prosecutor Jonathan Polnay said: "He feels the offence has affected his life quite a lot. He doesn't see his friends outside of school.
"He has also split up with the girl who was his girlfriend at the time."
He continued: "He said he is now worried and scared of older men and what they might do. He says he doesn't know the man who did this to him and he is very scared for his life if he was to come in contact with him again, because the attack on him was so random."
Coe was convicted in August following a trial at Southwark Crown Court of assault occasioning actual bodily harm and battery in Wilson Road, Newham, on April 15.
He appeared relaxed throughout the majority of the hearing, smiling and leaning back in his seat with his hands behind his head, and his legs up against the dock wall.
However, he dropped his head in his hands as Naeem Mian, defending, told the court of his "troubled past".
The court heard Coe had grown up knowing that his mother had been abused by his father.
Mr Mian said this had caused the attacker to become guarded of his personal space.
He also submitted that despite his size, Coe had been the victim of many attacks in prison.
"He has been stabbed in the neck, he has had boiling water poured over him and he has also been attacked in numerous other ways," he said.