Al-Subaiy has been engaged in terror-support and financing since at least early 2003.[2] He has been accused by the United States Government of lending support to Khalid Sheikh Mohammad, the mastermind of the September 11th attacks on the World Trade Center, as well as "providing support to al-Qaeda senior leadership in Pakistan's tribal region". Al-Subaiy has also worked to move extremist recruits to al-Qaeda training facilities in Pakistan and South Asia.