I'd like to give an opinion from personal experience. As an author of 5 published books I am quite aware of copyright laws, and it may surprise you to know that a lot of authors are not against having their books bought then shared, sold and resold through used bookstores or garage sales. Many of us believe it broadens our ability to reach new readers and it actually does happen, a lot. Once you have a devoted following, they would prefer to buy your next book new! (and signed) They will watch for new releases and hang onto that book. So in our opinion, as long as they do not copy it for resale use, then we have no problem... but that's just the opinion of a lot of my author-friends and :-D