On a related note, some people believe that you shouldn't take pictures inside of churches, cathedrals or other religious buildings. This is most commonly seen in European countries, although it does come up in third-world countries' bigger cities as well. What you'll find is that the more tourists there are, the more restrictive it is to shoot inside. Why? The most common reasons are that it's disrespectful, and the flash can damage the paintings. As for respect, churches (especially larger cathedrals) have no such edict in scripture or tradition that says that artistic reproduction (photographs) of the House of God is disrespectful. In fact, the Catholic Church has always advocated the practice of imagery—especially of its architecture and icons—as this serves to "spread the word." As for flashes hurting artwork, that's simple: a flash usually bursts for 1/250th of a second, so it would require 250 people to take pictures continually for hundreds of years in order to get the same amount of light that a normal overcast day would put in a church. So, it's not about damaging art work.
However, there are very good reasons for not photographing inside of a church or other such buildings. First, churches with many tourists have a lot of people that are not there to worship, interfering with the local few who are. It's not too hard to keep most people quiet, but having a lot of bursts of light can be really distracting to someone trying to communicate with the almighty of their choosing. Secondly, and try to take this for the economic reality that it is (and not the cynical voice of a photographer), churches make a lot of money selling postcards to tourists who can't take pictures for themselves. I've spoken to many clergymen at such churches about this edict, and they freely admit—even brag—about how much money is made on postcard sales when photography is restricted. If you still think I'm just being cynical, let me also point out that this is a good thing: churches often need more money than they can raise on their own, and if they can do it by selling postcards, then more the power to them. It's just sardonic to see a church telling a white lie just to make ends meet.
Back to the point though: most churches have no problem with your taking pictures. In fact, this is more the rule than the exception. In any event, you should always respect the rule of the land, as it were, and don't try to skirt around them. You'll find your photos to be far less interesting if you have to "sneak them."
