Imagine for a moment that you're in the middle of WWII (instead of the current WWIII). You live in England. Bombs are falling from the skies on the factories in Birmingham and Liverpool. So the government puts out a hightened warning for people who work or live in factories. Everyone else, be vigilant, but you don't need to worry as much as those in and near factories. Sounds preposterous, right? I mean bombs could start falling anywhere (and they did).
This scenario is no different than what actually happened yesterday with this idiotic terrorism warning light system in the U.S. Transit was hit in London, so U.S. Homeland Security raises the threat level to orange, but for mass transit only. So just because bombs went off on a bus and in subways in London, that's the only place terrorists are thinking about right now? Come on.
Sure, security should be heightened...everywhere. The press conference to announce the changing of colors from yellow to orange for mass transit was for PR only. I noticed several mayors announcing this morning that they've taken it upon themselves to increase security in more areas than mass transit. Duh.
It seems that if you're in a war with an unknown and unpredictable enemy that it's easy to assume their targets will be random and unknown. Now we have pick and choose warning systems.