Today it is not only possible, but also very easy to manipulate and re-arrange a picture with the many efficient and easy-to-use computer programs, which are available for everyone. You can easily get fooled, but computer-manipulated pictures are here to stay whether you like it or not. I prefer the positive attitude, to see the possibilities, while I also realize, that the technique often is (and will be) misused. My personal opinion is, that if a picture is manipulated, whether it is performed by a computer or some other means, it must be clearly stated. Below you can see a number of examples.