I have to agree with the above poster. I just posted in another thread that I've been to Belfast several times and have hundreds of pictures of murals. I have never had any problems. I've had a few people shake their heads at me, or little kids ask for a pound or two to "paint the sidewalk" or for "taking pictures", but that's about it. I've never heard about taking anybody's permission if they are in the picture, but I don't really have any people in my shots. I would agree though, that if there are a lot of people around, and it just doesn't seem right, then move onto the next mural.

I have also always walked through the Falls and Shankill areas as well. It has been five years since my last visit, but there is a spot in downtown Belfast where the black taxis pick up passengers. However, there are the "Catholic" taxis that go up to the top of the Falls area and back downtown and there are "Protestant" taxis that go to the top of the Shankill area and back down. You can usually tell if they have a shamrock or an orange poppy in the window. They take a few people at a time and both pick up and drop off along the way. It was 50p per person five years ago. I usually take one taxi to the top of one area, walk back down and then take another taxi to the top of the other area. It is a lot of walking though.

Feel free to PM me if you have any other Belfast questions. You'll have a great time there.