The basic flaw here is that Oyster cards can only be tied to an individual if they're actually registered. If you use a pay-as-you go card and load it up with cash at a newsagent's there's no way they can trace your movements. So, uh, what would a terrorist do? Or would using a PAYG card count as "suspicious behaviour" in itself, like having several mobile phones?
You can register pay as you go oyster cards, I choose not to. Everything you do these days is being watched by someone, how many cameras catch you on tape just walking to work? It's frightening! Orwell was definitely on the right tracks!
I can't even go to the loo in peace. Camera's are even installed in public lavs. I think they can track people using unregistered oyster cards. Simply by using a combination of camera and journey data. Ever notice that you can see where you have been? It wouldn't surprise me if MI5 knew more about my whereabouts than the entire length of my colon
Still you know what they say, if you've got nothing to hide you've no need to worry. Everyone who's got nothing to hide, please post here. Under your real name of course ...
First they came for the addicts, I remained silent; I was not an addict. Then they came for the teenagers, I remained silent; I was not a teenager. Then they came for the Muslims, I did not speak out; I was not a Muslim. Then they came for the radicals, I remained silent; I was not a radical. When they came for me, there was no one left to speak out.