Breaking news. Anjem Choudary convicted of inviting people to support Islamic State.

Choudary, 49, drummed up support for the militant group in a series of talks posted on YouTube, the Old Bailey heard.

He was convicted alongside his confidant, Mohammed Mizanur Rahman.

The Met Police said many people tried for serious offences “attended lectures or speeches given by these men”.

Counter-terrorism chiefs have spent almost 20 years trying to bring Choudary, a father of five, to trial, blaming him, and the proscribed organisations which he helped to run, for radicalising young men and women.

But it’s tricky, because free speech.

Both men were charged with one offence of inviting support for IS – which is contrary to section 12 of the Terrorism Act 2000 – between 29 June 2014 and 6 March 2015. The verdict on the two defendants was delivered on 28 July, but for legal reasons can only now be reported.

They made the mistake of swearing allegiance to IS, and publicly announcing it. (How? Twitter, of course. The sixth pillar of Islam, al Twitter.)

Choudary was once the spokesman for al-Muhajiroun, an organisation that can be linked to dozens of terrorism suspects.

Its leader Omar Bakri Muhammad fled the UK after the London suicide bombings on 7 July 2005. Over the years since, Choudary has become one of the most influential radical Islamists in Europe and a string of his followers have either left the UK to fight in Syria or tried to do so.

People used to tell me, when I blogged about him, that he was just a joke.

Supporters of Choudary included:

• Michael Adebolajo and Michael Adebowale, the murderers of soldier Lee Rigby
• Suspected IS executioner Siddhartha Dhar
• Omar Sharif, a British suicide bomber who attacked Tel Aviv in 2003
• Brusthom Ziamani, jailed 12 years later for planning to kill in the streets of London

But he didn’t murder or execute or kill people himself – he just inspired other people to do that.

Rahman used Facebook to tell people to join IS.

Commander Dean Haydon, head of the Met Police’s counter-terrorism unit, said the case which led to the conviction of Choudary and Rahman was a “significant prosecution in our fight against terrorism”.

He said: “These men have stayed just within the law for many years, but there is no-one within the counter terrorism world that has any doubts of the influence that they have had, the hate they have spread and the people that they have encouraged to join terrorist organisations.

“Over and over again we have seen people on trial for the most serious offences who have attended lectures or speeches given by these men.

“The oath of allegiance was a turning point for the police – at last we had the evidence that they had stepped over the line and we could prove they supported ISIS.”

Until then it was free speech.