As usual, nothing achieved...
As with many things, whilst it's always convenient to blame cops and politicians, often easily-influenced and hysterical members of the public also cause as many problems. And so now we live in a culture where people fear being photographed despite the fact there's suveillance everywhere.
And I'm not talking the fat ugly miserybag in your company's finance department who refuses to have her photo taken for her work ID card. No, I'm talking your "Oh no, he must be a paediatrician [sic]!" flustered parents, regardless of the fact that the kid probably wasn't the sole 'subject' of the image.
The only time I took photos on an underground train, the Paris Metro, the only person who interfered was a guy who insisted he should be in one of them, and stood grinning madly in front of me while I took it. Upon checking the picture on the LCD, he seemed happy enough and went and sat back down!
People in this disappointing country of ours need to lighten the f'ck up, and stop believing that everything is so dangerous and out to get them. I thought this was why we had dramatic sitcoms, so that those with boring lives could live 'by proxy' through the make-believe existences of others. Perhaps Corrie or EastEnders should introduce more terror-related storylines to keep these drama-mongers content while the rest of us just get on with our own lives.