Consider this: I buy a book. I then loan it to 5 friends. Then it turns out to have a misprint, and collectors are willing to pay top dollar for it. So I sell

Consider this: I buy a book. I then loan it to 5 friends. Then it turns out to have a misprint, and collectors are willing to pay top dollar for it. So I sell it at a profit. I end up with more money than the author for that book. 7 people have gotten the utility for the book, and the author only got compensated for one reading of it. Does this make me a thief? What about your local library, hundreds of people can get the utility from one copy of a book, and the author gets nothing. Now, a book an song are different, and copying allows me to potentially get simultaneous utility from the song (I listen to it at the same time as my friend). However, I bet we don't both listen to it on continuous loop, and further I bet the time spent not listening to the song by both of us in copying situation could be mostly mimicked by a complex sharing agreement. There have been many times when I had roomates where we avoided paying tons of money on music CDs by pooling in just such a scheme -- it was as if our music collection was effectively 3 times the size (before burning was common and cheap). So when does it start being theft? At the copying? At the depriving of some theoretical profit? At the point where I deviously get 66% discount on my music by sharing a piece of plastic? Why is the library not considered the moral equivalent of the song sharer?