“An official with the Transportation Security Administration, who asked not to be named, said Wednesday that the agency was aware of the photo but viewed it mostly as a ‘propaganda’ piece rather than evidence of specific planning.
The official noted that the magazine did not refer specifically to SFO’s AirTrain people mover and said the picture was believed to be a ‘stock photo.’
‘We’re not aware of any specific threats to the San Francisco area,’ the official said.”
Source:Al Qaeda runs photo of SFO tram: ‘Assemble your bomb’ – SFGate