Cultural purposes? Like, "Its part of our culture to kill as many of the infidel as we can."
http://www.guardian.co.uk/alqaida/story/0,12469,1143626,00.html
Terrorist bid to build bombs in mid-flight
Intelligence reveals dry runs of new threat to blow up airliners
Jason Burke, chief reporter
Sunday February 8, 2004
The Observer
Islamic militants have conducted dry runs of a devastating new style of bombing on aircraft flying to Europe, intelligence sources believe
-snip-
The warning, passed to Western agencies by Middle Eastern intelligence services, is based on interrogations of Islamic militants captured in the Arabian Gulf and is corroborated by intercepted communications between terrorist cells and interviews with prisoners held by the US government at Guantanamo Bay.