I was in Laos and Cambodia around 2001/2 and was advised when talking to hill tribes to always ask before taking pictures, the kids loved it, especially seeing

I was in Laos and Cambodia around 2001/2 and was advised when talking to hill tribes to always ask before taking pictures, the kids loved it, especially seeing themselves on a digital camera, however the older generations usually didnt want to be photgraphed (we were advised that it was usually for this reason but I never pushed it).