“Behead those who insult Islam” is quotation from a sign that has appeared at many rallies. The first appearance of the sign was at a February 2006 rally in London, organized in protest of the Muhammad cartoons published in the Danish newspaper Jyllands-Posten on September 30, 2005.
 
“Behead those who say Islam is violent” has been cited in print since at least December 2007. A poster with this slogan and “ISLAM. It’s a Religion of Peace…seriously!” was cited in print in 2012. Two Muslim men beheaded a British soldier on a street in London in May 2013, causing renewed public comment on the “Behead those who insult Islam” and “Behead those who say Islam is violent” slogans.
 
   
Wikipedia: Jyllands-Posten Muhammad cartoons controversy
The Jyllands-Posten Muhammad cartoons controversy (or Muhammad cartoons crisis) (Danish: Muhammedkrisen) began after 12 editorial cartoons, most of which depicted the Islamic prophet Muhammad, were published in the Danish newspaper Jyllands-Posten on 30 September 2005. The newspaper announced that this publication was an attempt to contribute to the debate regarding criticism of Islam and self-censorship. Muslim groups in Denmark complained, and the issue eventually led to protests in many countries around the world, which included violent demonstrations and riots in some Islamic countries.
 
Danish Muslim organisations that objected to the depictions responded by petitioning the embassies of Islamic countries and the Danish government to take some form of action in response, and filed a judicial complaint against the newspaper, which was dismissed in January 2006. After the Danish government refused to meet with representatives of the Islamic countries and would not intervene in the case, a number of Danish imams made trips to the Middle East during the autumn of 2005 to raise awareness of the issue.
 
After the issue received prominent media attention in some Islamic countries, Muslims held protests across the world in late January and early February 2006, some of which escalated into violence resulting in a total of more than 200 reported deaths, attacks on a number of Danish and other European diplomatic missions, attacks on churches and Christians, and a major international boycott.
       
The Telegraph (UK) 
Democracy has a gun held to its head
12:01AM GMT 05 Feb 2006
Last week, Muslims marched in the centre of London chanting “Freedom go to Hell!” There could be no more graphic illustration of the paradox at the heart of the cartoon row. These protesters were exercising - and in many cases abusing - the freedom of protest and freedom of assembly that are foundation stones of British democracy. Yet, even as they exploited these hard-won liberties, they were calling for them to be abolished.
 
This newspaper would not have published the cartoons of Mohammed at the centre of this controversy, images which we regard as vulgar and fatuously insulting. But - and this is the crucial point - we reserve absolutely our right to make our own decision, free of threat and intimidation. The difficulty is that what started as an issue of editorial judgment has become a question of public order. The protesters in London with their disgraceful slogans - “Behead those who Insult Islam”, “Britain you will pay - 7/7 is on its way” - have made it all but impossible for a genuinely free debate on this issue to take place. All such debate is now being carried out in the shadow of murderous intimidation.
 
Science Notes
“Behead those who say Islam is violent”
December 1, 2007 — monado
Y’know, I always hoped this was a sick joke. It does sound like something out of the Goon Show, or Monty Python, This Hour Has 22 Minutes, or The Colbert Report.
(“BEHEAD THOSE WHO SAY ISLAM IS VIOLENT” sign is shown—ed.)
UPDATE: Reader Stanislaw Pak points me to this version, which apparently is the original. So the image above was altered to make it ironic.
(“BEHEAD THOSE WHO INSULT ISLAM” sign is shown—ed.)
 
International Business Times
Muslim scholar’s “anti-terrorism camp” is a welcome development for community relations in Britain
August 8, 2010 10:04 PM GMT
(...)
However for as long as a community is widely represented by criminals like Hamza and distasteful individuals such as Choudary and those who carry signs reading “behead those who insult Islam”, rather than by Dr Tahir-ul-Qadri or the Muslim gentlemen pictured paying his respects to slain British soldiers at Wootton Bassett, one could argue that people have a right to be concerned about the increase of that community’s presence in Europe.
 
Tea Party Command Center
behead those who say islam is violent
Added by Bellato Domina on April 6, 2012 at 4:58am
(From a poster/sign—ed.)
BEHEAD THOSE WHO SAY ISLAMD IS VIOLENT
ISLAM
It’s a Religion of Peace…seriously!
   
The Telegraph (UK)
Woolwich attack: Suspect Michael ‘Mujahid’ Adebolajo led away in handcuffs at fanatic’s trial
At the time, it seemed like just another ugly scuffle in a long line of clashes between the police and a rag-tag group of Islamist extremists.
By Tom Whitehead, David Barrett and Steven Swinford
10:22PM BST 23 May 2013
The setting was the Old Bailey in 2006, where four men were arrested for fighting with police and photographers as they turned out in support of a fanatic on trial for calling for British soldiers to be killed.
 
Among those led away in handcuffs that day, still arguing that he was within his rights to urge people to “behead those who insult Islam”, was Michael “Mujahid” Adebolajo. Seven years on, Adebolajo, a British-born Muslim convert, is suspected of having answered the call to arms as one of two men who butchered Drummer Lee Rigby in Woolwich.
 
The Truth Shall Set You Free
May 23, 2013
Islamic definition of “tolerance” – “Behead those who insult Islam”
http://www.hoax-slayer.com/muslim-protest-london.shtml
View these photos of placard-wielding Muslims in 2006, then ponder this question, ” Who or what “radicalised” those two savages who mercilessly killed the soldier yesterday?