A surprisingly frank piece from the New York Times on the disturbing prevalence of violent jihadist rhetoric in Britain: British Law Against Glorifying Terrorism Has Not Silenced Calls to Kill for Islam.

LONDON, Aug. 20 — From his home on the northwest edge of this city, Muhamad al-Massari runs a Web site that celebrates the violent death of British and American soldiers. It is visited by tens of thousands of people every day, he said.

Mr. Massari maintains the Arabic-language site, tajdeed.org.uk, in the face of a strict new law aimed at curtailing violent speech and publishing. Just last week, the Council of Holy Warriors, a group affiliated with Al Qaeda, posted a declaration on the site praising a suicide bombing in Iraq that killed or wounded 55 people.

“If you kill our civilians, we kill your civilians,” Mr. Massari declared during an interview.

Mr. Massari’s Web site, and his public remarks, appear to violate of the Antiterrorism Act of 2006, which makes it a crime to glorify or encourage political violence. Inciting violence has long been illegal here but the new rules, drawn up after the London subway and bus bombings in July 2005, are intended to be much tougher.

The law’s underlying assumption is that speeches and publications by Britain’s more extreme Islamists may play a role in leading disgruntled young men toward violence. In addition to banning speech that encourages terrorism, the new law also criminalizes reckless speech that may have the same effect.

Yet despite the antiglorification law, and an array of other measures approved since last summer’s bombings, Islamist leaders like Mr. Massari persist, some of them declaring it the duty of British Muslims to kill in the name of Islam.

Some British leaders are beginning to publicly question why such clerics are allowed to continue.