A man protesting against the Danish Muhammad cartoons called for the beheading of Islam's enemies
Mizanur Rahman, 23, a web designer of Palmers Green, north London, denies inciting murder and using words or behaviour to stir up race hate.
He addressed the protest in London on February 3 on the issue of UK troops.
Prosecutors said Mr Rahman had told the crowd: "We want to see their blood running in the streets of Baghdad."
David Perry QC said Mr Rahman had carried placards saying "behead those who insult Islam" and "annihilate those who insult Islam".
He said: "Annihilate and behead are ordinary English words with the ordinary English meaning of kill."
Mr Rahman also called for a wave of attacks across Europe in the manner of 11 September, Mr Perry said. A video of his megaphone-amplified speech would be played to the Old Bailey jury.
He allegedly told fellow demonstrators: "Oh Allah, we want to see another 9/11 in Iraq... in Denmark... in Spain... in France... all over Europe. Oh Allah, destroy all of them."
Usual suspects in 'rent-a-mob'
Faces of evil
Choudary justifies 7/7 as self-expression