As I said, in the US such a statute wouldn't ever apply to the press. I guess I just take that for granted.
I had thought the UK had similar protections, but if a simple London city ordinance can take precedence, that is surprising ... to me.
Have you now actually read the passage in question? ... your initial response gave hints that you may not have actually read it ...
I'm interested in your assumption that it wouldn't apply to the press. I wonder why you think that. Over here, the law would be valid. Since it's secondary legislation (that is, a rule made under the provisions of an Act of Parliament), it could be quashed by the High Court as being, perhaps, outwith the ambit of that Act (ultra vires) or disproportionate. It would take someone with sufficient interest (by which I mean involvement) to apply for judicial review.
Of course I read it: first thing I did. I'd never comment on someone's interpretation of something like that without reading it for myself.
What I was getting at in the last paragraph of my first response was the underlying reason for the byelaw. There have been several "camps" of one sort or another set up in London. The most recent was of the "occupy" series, but there was a long-standing one which made an area near the House of Commons a real eyesore. I strongly suspect that it was felt that if the camps couldn't be photographed, and hence were deprived of what Mrs Thatcher described in relation to the IRA as "the oxygen of publicity", they probably either wouldn't start in the first place or wouldn't last long.