UK restrictions on photography in public places

I came across a short video documentary from Current about UK restrictions on photography in public places on BoingBoing today. As someone who carries a camera almost all the time, everywhere because I truly enjoy photography, I am terribly disappointed by the new trend where people being harassed for either taking photos or video taping in public spaces. UK like Canada or US suppose to be a free society where we should be allowed to do things within what is allowed by laws. This is not first time in recent months I have heard about incidences like the one presented in this short video. I have had a my own problems with security on a subway platform last year where I was questioned why I am taking photos, while there is no law actually preventing me from doing so in Canada. I understand the current worldwide climate and the politics of fear which has been successfully sold to us over the recent years. But while we all should be a little more cautious, there need to be common sense as well.