It's funny, because English law called copyright “copyright”, the right to copy. The French call it droit d'auteur, which is deeper; it's the artist's right. The inclusion of moral rights kind of makes it that. It's your right to be credited or to remain anonymous, your right of the integrity of the work. People can't mutilate or overprint or crop your work or print it badly or destroy it without your approval. There's the right that I mentioned that K'naan invoked, that you can refuse to have your work associated with causes you don't approve of, which might damage your reputation. These are protections for an artist's reputation.
Regarding the photography instance I brought up, I said that if you give control of your work away to someone else so they can make copies without your input, it goes to the moral right if you can't control the quality of your work. If a bad copy is circulating and there are many bad copies around, you look bad. Similarly, with the user-generated, non-commercial content business.... I've seen artists where somebody has taken works and done things to them and put them back up on the Internet, and the artist's name is attached to them still. Yes, they've credited that artist, but the artist looks ridiculous, and they're not happy about it.
These are instances of moral rights infringements. Some of them are enormous, and some of them are very small, but it has to do with the artist protecting their reputation.