Greater London has over 900,000 Muslims, (most of South Asian origins and concentrated in the East London boroughs of Newham, Tower Hamlets and Waltham Forest), and among them are some with a strong Islamist outlook. Their presence, combined with a perceived British policy of allowing them free rein, heightened by exposés such as the 2007 Channel 4 documentary programme Undercover Mosque, has given rise to the term Londonistan. Following the 9/11 attacks, however, Abu Hamza al-Masri, the imam of the Finsbury Park Mosque, was arrested and charged with incitement to terrorism which has caused many Islamists to leave the UK to avoid internment.[citation needed]