By Dominic Casciani
Street campaigning and agitation: An al-Muhajiroun poster
Al-Muhajiroun, also known as Islam4UK, was the group that claimed it would march through Wootton Bassett. Now the group faces a UK ban on grounds of national security.
Al-Muhajiroun, in its various forms, is an important part of the story of Islamist anger and the line between politics, protest and national security.
The organisation is made up of a small band of tight-knit young men who advocate a worldwide Islamist system of government and, at the same time, vehemently denounce the foreign policies of the US and UK.
It has had a knack of staging attention-grabbing stunts with its leaders adept at finding ways of provoking a backlash from the press and some politicians. Now that tactic of agitation and provocation has led to its ban under terrorism laws.
Al-Muhajiroun was originally formed by Omar Bakri Mohammed, the extremist preacher. He founded the organisation after quitting another Islamist group, Hizb ut-Tahrir, which wasn't radical enough for his views. But what he took with him was its strategy of building a following by setting up cells of supporters in every town possible.
Bakri developed an almost clownish media profile - he enjoyed appearing on the front pages of tabloid newspapers. But behind the scenes, his views and lectures were were playing an important role in the radicalization of some young men.
He and his followers would tour the country, holding small study circles where he talked about religion and politics - and argued that Muslims had no allegiance to the UK, only to God. He built on Muslim anger over the Middle East, the problems in Pakistan and Afghanistan and elsewhere.
So while his former friend and rival Abu Hamza would preach from the mosque he controlled at Finsbury Park, Bakri and al-Muhajiroun would travel and target any community where they could get a foothold.
Critically, within Muslim communities, he sought to open a debate on the traditional Islamic thinking that Muslims living in a non-Muslim country have a "covenant of security" with their neighbours, providing they are treated as equal citizens.
He argued that Muslims around the world were victims of Western aggression - and therefore British Muslims were also fellow sufferers. He left the conclusion open to interpretation, saying that it was up to the individual to decide whether the covenant had been broken. Some of his followers concluded that it had, and ultimately supported a violent response.
Despite that ambiguity, the organisation's conferences and events were more explicit. One of al-Muhajiroun's most infamous events was billed as celebrating the "Magnificent 19" plane hijackers who had taken the fight back to the West. It got them in the headlines - but also led to increasing of its members by the security services.
Bakri himself disbanded al-Muhajiroun in late 2004. He later blamed the British people for the 7 July 2005 attacks on London - before fleeing to Lebanon.
Bakri: Fled the UK in 2005
He has continued to preach to followers in the UK over the internet - his talks are relatively easy to find - but he is banned from entering the country.
But while the original organisation was officially dead, its British supporters reappeared under various banners over the next five years.
One of these, the Saviour Sect, theatrically stormed a 2005 general election rally to debate how Muslims should vote, declaring that any who did so were apostates punishable by death.
The other group, Al-Ghurabaa, hosted links on its website to hardline forums which justified suicide bombings. The Home Office subsequently banned both groups.
Last year, some of al-Muhajiroun's original followers started campaigning for their brand of worldwide Islamic rule under the name Islam4Uk. Its website carried a picture of Buckingham Palace converted to a mosque.
Months later they declared they were "reforming" al-Muhajiroun itself because the organisation had never actually been banned.
With Bakri out of the country, the leadership of Islam4UK/al-Muhajiroun has fallen to former lawyer Anjem Choudary.
Anjem Choudary: Prolific media performer
He is adept at capturing the media's imagination - but is also widely despised by ordinary British Muslims.
Some of the group's other supporters have been convicted or implicated in serious offences.
In 2006, Abu Izzadeen, also known as Omar Brooks, infamously heckled the then Home Secretary John Reid. He was later jailed for seeking to raise funds in 2004 for mujahideen fighters in Iraq.
In a separate trial, two men who attended a rally over the global Danish Muhammad cartoons row, organised by al-Muhajiroun's successor, were also convicted of soliciting to murder.
Mr Choudary claims that men like these have been denied free speech.
But what is clear is that there are also men who have attended al-Muhajiroun events who have gone further than words.
Omar Khyam was the ringleader of a major plot to bomb targets in south-east England and had attended al-Muhajiroun meetings in his home town of Crawley.
Another British man who carried out a suicide attack in Israel was also linked to Omar Bakri.
Islam4UK/al-Muhajiroun's leaders have a track record of planning events that never actually happen, like the Wootton Bassett protest. Nevertheless, they cause an enormous media uproar and a great deal of hurt among ordinary Muslims who say they are drowned out.
On other occasions, supporters have spontaneously appeared on the streets, such as last year's tense scenes in Luton when they protested against a march by the Royal Anglian Regiment.
But while this may appear amateurish or attention-grabbing, counter-terrorism experts have remained concerned that the angry message feeds into a broad strand of extremist Islamist activism - much of it taking place beyond public view.