Quote: Although saying this I often saw tourists snapping away whilst waiting for trains with no problems and taking pictures of the soldiers/guards at Tianamen square is fine.
Not always - one guard sternly shooed me away when I asked permission to take his pic outside the gates of the Forbidden City. But yes, I found that in general a lot of people were happy to have their picture taken when asked, but many weren't. Fair enough.
If you're obviously non-Chinese you'll also find yourself the subject of Chinese photographers - on our month long trip a couple of years back I must have had my picture taken a dozen times, usually with the snapper's smiling family. It's a fantastic country. I loved every second of it.