Actually, if you’ll recall, it’s a method that had been in used many times to great effect in countries in which terrorist bombings had already become routine, and the NYP article was prompted by widely-publicized alerts to be on the look-out for false emergency vehicles or people trying to acquire them, which came after two Pakistani men unsuccessfully (and quite innocently) attempted to buy an ambulance in New Jersey.
The possibilty of terrorists’ use of emergency vehicles was already on the table, because it had already been established that that’s something terrorists do, and NYC officials were warning the public that they had concerns baddies were planning something similar in NYC. It was the talk of the town already.
The NYP article led almost immediately to tighter controls being placed on the over-the-counter sale of official-looking decals for emergency vehicles, because public awareness helps get things like that moving. Even with all the security warnings, Manhattan businesses were quite happy to hand over these items for a few hundred bucks, with practically no questions asked. That’s clearly an intolerable situation that you want to correct as soon as possible.
The NYP did not name the store that provided the decals, or the dealer who supplied the roof-rack so it’s not like they were advertising for them. Is pointing out that you can buy replica police gear in Times Square a security risk? Anyone who desired to have such things would have no trouble finding them-- You know-- advertising. The article provided no intelligence or ideas that would not already be obvious to a potential car-bomber – only a fire under the ass of the people who needed to change the situation.
You’ve got a situation that needs to be changed immediately in the interest of public safety. At the same time, no laws are apparently being broken. People are generally resistent to voluntarily act in such a way as to reduce their income. You think that the responsible thing to have done would have been to write a couple of letters and phone a few people and just hope that everything worked out before someone got killed? Direct pressure from the public works a lot faster, sometimes. A business-owner who knows that sixteen million people are concerned that he might be putting them at risk may drop his “It’s a free country – I ain’t breakin’ any laws” attitude a bit quicker.