apologies to paul, but he seems to be misapplying the concepts of privacy outside the scope where it makes sense. i've seen similar things in my professional career as well. even so-called 'privacy experts' seem to want to try and get the benefits of privacy in situations where it just doesn't work.
privacy has limits. there are situations where the strategies that comprise privacy make sense and work well and there are situations where they fail for practical reasons. it doesn't matter if keeping X private would be useful or desirable, if the practical realities prevent it then privacy is the wrong tool. being out in public where everyone can see you is one situation where privacy logically can't work (unless perhaps you wear a shroud, but even then only if lots of other people are wearing shrouds too and only if one can't tell the shrouds apart).
i see london,preventing filming in public doesn't protect or restore anyone's privacy. if you're in public then the public can still see you, they can see where you're headed, what you're wearing, what you're holding, who you're with, etc. everything that could be photographed can still be seen by the people around you. all preventing filming will do is make it more difficult to disseminate the information you were misguidedly trying to keep private in public. that information hasn't really remained private, it's just harder to share in some cases.
i see france,
i see the colour of paul ducklin's pants.
one wonders, if public photography were limited (and british cops, with their penchant for harassing photographers, would love such a policy) what would come next? would public twittering become outlawed? after all with a cellphone i could just as easily tweet that tom cruise and katie holmes are walking down john street and give away as much information as i could with a photo, if not more (a photo might not give any geo-location data - and real-time geo-location data is something celebrities really don't want getting out there). perhaps we should outlaw public observation in it's entirety.
in order to effectively protect ourselves it's important to know when and how to apply the various protective strategies at our disposal. privacy doesn't work in public - you can't magically stop people from seeing/hearing/sensing you. when we step out into a public space it should be understood that everything people can see or hear is no longer hidden and therefore not private. if there's something we want to keep private it's necessary to keep it hidden away where people can't get access to it, which means not bringing it out into a public space.