The incident last June 16 2007 which I discussed in an earlier post has prompted me to do a research on Photographer's Right. But before that, let me clarify that I am not a lawyer and this post was written on a photographer's perspective and neither take this as a legal advise.
Based on my research, I found that there is really no written law or a specific legal prohibition that limit or prohibit anyone from photographing in public places/ public structures (unless of course there is a city ordinance stating a legal prohibition on photography). I also found useful guides which can be used by photographers as reference. But these guides vary from country to country. So far, the guidelines on Photographer's right I found are from the United States, UK, Canada, Ireland and Australia. Contents of these guidelines needs to be modified for applicability in Philippine context. But I think, since many of our laws was based on the US, we can refer to the US version as reference. All invoked their rights based on their Constitution (as for the Philippines, it's under Section 4 of the 1987 Constitution which partly reads "No law shall be passed abridging the freedom of speech, of expression, or of the press..."). No articles was found on photographer's right with basis on Philippine Law.
As mentioned, there is no written law that prohibit photographers from doing photography in public places but it's quite ironic that photographer's right is now being curtailed around the world. It was observed that assaults on photographer's right has changed drastically since 9/11 and the world is far more 'security conscious' than it ever used to be. Photographers in the US especially photojournalists have faced an increasing wave of harassment, intimidation, and obstacles often in the reason of national security (see 'Patriot Act'). By far, New York has been the most strict in imposing photography restrictions. Recently there has been a Petition called "Picture New York" (see also New York Times' article as reference) which calls upon the city to dismiss restrictions on photography. The much publicized internet campaign collected at least 31,000 signatures and brought New York City Government to Rewrite Proposed Rules on Photography Permits.
Some countries including Australia and New Zealand manifest worrying trends, their Governments charge high fees on photography of National Parks as Nick Rains wrote in his article The Erosion of Photographer's Rights. Aside from security, issue on privacy is another thing (see Photographers Guide to Privacy).