The Hofstadgroep is the Dutch secret service nickname given to a loose collection of Muslim extremists, nine of whom were convicted of terrorist offences in March 2006 and sentenced to between one and 15 years in jail. The group is said to include Mohammed Bouyeri, who murdered film-maker Theo van Gogh, and Samir Azzouz who was finally convicted of plotting terrorist attacks in 2007 after twice being acquitted.