For almost two years, intelligence services around the world tried to uncover the identity of an Internet hacker who had become a key conduit for al-Qaeda. The savvy, English-speaking, presumably young webmaster taunted his pursuers, calling himself Irhabi -- Terrorist -- 007. He hacked into American university computers, propagandized for the Iraq insurgents led by Abu Musab al-Zarqawi and taught other online jihadists how to wield their computers for the cause.

Suddenly last fall, Irhabi 007 disappeared from the message boards. The postings ended after Scotland Yard arrested a 22-year-old West Londoner, Younis Tsouli, suspected of participating in an alleged bomb plot. In November, British authorities brought a range of charges against him related to that plot. Only later, according to our sources familiar with the British probe, was Tsouli's other suspected identity revealed. British investigators eventually confirmed to us that they believe he is Irhabi 007.