Here's one example from JI http://en.m.wikipedia.org/wiki/Singapore_embassies_attack_pl...

Here's a reconnaissance manual: http://ruckus.org/article.php?id=809

In general, blacklisting or whitelisting specific techniques is not the path to security. Looking for people conducting surveillance activities around targets is a good way to catch terrorist plots before they execute. The alternative, catching them after they execute, is not particularly good.

The only mention of photography in that example was of a military base. There aren't likely to be publicly available photos of a military base, so I can see why you'd want photos for planning.

This is completely different from a public landmark in the US which for which you will easily be able to find hundreds or thousands of photos from every conceivable angle.

I've still yet to see any evidence that overt photography or a public landmark would be useful to a terrorist, or any evidence that this has actually happened with enough frequency to classify photographing landmarks as suspicious behavior, or for that matter ever happened at all.

I'm not denying that terrorists conduct surveillance. What I'd like to see is evidence that they do so through overt photography of public landmarks and buildings.

If we stop investigating only potential surveillors who take photos as a matter of policy to to blog complaints, doesn't that make it easy to hide surveillance operations from scrutiny by just having everyone bring a camera along?

It wouldn't make sense to ignore other suspicious activity just because the suspect has a camera. My point is, are we justified in treating photography alone as a suspicious activity?