Someone Else - many thanks, had no idea - I sit corrected.
Amoeba comments - oh sure, I don't disagree - by no means in favour of phones on planes, I was commenting on the FBI issues.
FBI issues - as other posters have commented, there are other means of communication. WLAN means instant messaging, even IP telephony. What tapping/control abilities have FBI over seatback phones? And a number of folks on 9/11 and other occasions managed to connect from aircraft with conventional cellphones... a Bad Guy determined to make a call will just sneak into the lavs with his phone and with luck he'll manage to connect... don't really see a major security issue with cellphones here.
R1