My workplace, a data center for a large banking company, has the same sign. It was a rule implemented by the security department. They don't want people casing the joint and getting significant details photographically. Makes complete sense to me. Given the power of telephotos, I'd think you'd pretty much tell people to keep their cameras in the cases. I suppose its a bummer for travelers who want to show airports their friends'll never see, but when it comes right down to it, the global security threat has to take precedence sometimes.
Blame the conspirators if you need to place blame, not the people fighting them.