Yeah, this is a “damned if you do, damned if you don’t” call for the security people. If they say nothing, and something happens, they’ll be crucified for not warning anyone. If they publish the warning and nothing happens, they’ll be crucified for raising a “false alarm.” If they publish the warning and something happens, they’ll be crucified for not doing enough. If they have the info, don’t warn anyone, and nothing happens, sooner or later someone will discover that they had this info and did nothing, but were negligent. None of this, of course, addresses that it’s possible that something is in the works but gets called off or is in some other way prevented because there is an increased alert.
Here’s a question for the more conspiracy-minded: If you were in charge, and you had evidence that you considered credible that there was a potential large problem brewing, what would YOU do? On do you believe that there’s no possibility that terrorists have evil designs, and that the powers that be are making the whole thing up? Personally, I find that last scenario the least credible of all, but to each his own.