The terrorists might not have even had an idea like this so the media could just be giving them some new and ways to cause destruction.
There supposedly were plans to also use crop-dusters, etc... and I'm sure there are copies of Goldfinger and Black Sunday in the Al Quaeda video library...
The bottom line, though is that truck, car, and vest bombs are more easy to obtain and use and are very effective... although hijacked airliners are probably "best" of all.
