If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
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3. Open Threads should be posted in Discussion, and not Main.
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A couple of ideas come to mind immediately:
-- Just like reading all your email is likely to turn up something that sounds bad, tracking all your movements is likely, just by chance, to turn up something that looks suspicious; you may have been seen near a known drug dealers' den, or bordello, or you often visit a person who has been convicted of a crime, or you have been seen near children's playgrounds too much.
-- Use of the CCTV footage to catch you in a lie--bearing in mind that everyday human life involves telling necessary lies every so often. This can make you look really bad--oh, no, he lied to his wife about where he was, maybe he had an affair. He lied in his political speech--who knows what he was doing in back alleys back then?
-- Using the CCTV to capture images of something that would be embarrassing in public. Of course, you would have to make a mistake to show something private in public, but CCTV has the effect of greatly expanding the effect of such mistakes. Imagine someone caught on camera in bondage gear, or kissing a member of the same sex (or just cheating on their spouse). Or wearing a symbol of a sports team that is accused of being racist.
-- Taking a CCTV image out of context
Of course, you're being too narrow by asking for a conviction; these can be used to damage someone without convicting him of anything. Driving a politician out of office or blackmailing someone is not convicting him, after all.
Ah, I see it was a failure of my creativity, cheers.