As a guy who was photographer before becoming a security professional, I understand frustration with such rules and regulations. However, the idea that terrorists do not photograph targets is patently false. Target selection and pre-attack surveillance, whether visual or photographic, are in fact typically the only signatures of the attack planning cycle which are visible to the target. No, the 9/11 terrorists didn't need to do it (edit: extensively, that is...they certainly did a thorough reconnaissance of their possible flight paths to their target in order to avoid obstacles...), and not every plan will involve surveillance. But surveillance occurred on the 1993 WTC attack and on the Kenya and Tanzania attacks on US embassies; in fact, the efforts of the surveillance detection teams at one of these embassies meant security was tighter on the attack day and the bomb's effect was severely lessened, as it could not be placed close to the building. Pre-attack surveillance was noted before the Kobar Towers bombing. It's standard practice, straight out of A-Q manuals easily found on the web and elsewhere.
Tactics aside, the point is that the people making these rules are not part of some grand conspiracy to take away rights--they're well-meaning people with a job to do. I applaud people for standing up for rights, and note along with many of you that Google Earth and the like are providing better pre-attack planning info than most of us could make through photography and a free rein. Nor does surveillance always involve photography.
If the overall effect of regulations on society's liberties is more detrimental than the risks, take action and talk to your legal representatives. But the guys pushing your representatives to make these rules won't see your viewpoint, as they have a job to do and are trying to do it as well as they can...no matter...and understand that your viewpoint as a photographer is only one among many others.
However, at least in the US, it's pretty well established that newsworthy public scenes can be photographed, whoever is in them. But if you start taking pictures of a military base gate and its security features, stand by to be hassled and/or worse.
I don't work in the US, though, and the local police here treat this stuff pretty harshly. Great for my security, personally. They tend to detain, and I get to talk to, everyone who takes photos--normally, I'm acting apologetic and embarrassed for the police "over-enthusiasm", and we sometimes have a laugh once it's determined that there's no ill intent. But we also make them delete any photos of the facility (never had a film photog come by...).
Word gets around, and anyone watching the facility knows we're keeping a sharp eye out. (And not just on photographers...I've tracked down many a car owner by his license plate and said hello...) Again, great for my security to have a reputation for this. No need to be a jerk about it on my part, but again--our reputation as paranoid and eagle-eyed means we're not likely to be selected as a target for the terrorist groups known to be targeting my facilities and the homes of my employees.
That's my reality...I know it doesn't jive with many of yours.