Abu Musab al-Zarqwai
Imaginary radical blamed for any number of bombings, beheadings and so on in Iraq. For the American forces and public Abu Musab al-Zarqwai fulfils a similar role to Emmanuel Goldstein in Orwell's 1984.
Big bomb goes off in Tikrit - must be the work of the Abu Musab al-Zarqwai group.