‘Suspicious’ photography?

The Los Angeles Police Department has issued a notice regarding its official terrorism handling policy, identifying photographers as potential terrorists if they don’t shoot the usual tourist’s places. The document reads:

Photography. Taking pictures or videos of facilities/buildings, infrastructures or protected sites in a manner that would arouse suspicion in a reasonable person. Examples include taking pictures or videos of ingress/egress, delivery locations, personnel performing security functions (e.g., patrol, badge/vehicle checking), security-related equipment (e.g., perimeter fencing, security cameras), etc.;

You may think it’s reasonable to check for suspicious behavior including taking suspicious photos, but what is suspicious behavior anyway? Did the 9/11 terrorists take photos of their targets in the days before the attacks? Not that we know. Did the terrorists who attacked the London underground take photographs first? Not that we know. Did the terrorists who attacked the trains in Madrid take photographs? Not that we know. As far as I know, there is not one single documented instance where terrorists did take the kind of action the LAPD describes, so why label photographers as potential terrorists without any reason?