With Amazon's popular highlights (ok, so my link is to the NYTimes not Amazon--it's a good article) you can now see other readers' notes on the ebook you're reading. Hmm. Sometimes I've enjoyed reading text books highlighted by other people, but other times the highlighting has been vapid--pencil or highlighting pen wavering all over the place, not helpful but distracting.
Of course, the simple solution is to turn off the feature--much simpler than erasing highlighting on paper.
But the fascinating point is that the feature exists.
Are books becoming mashable? And what will that mean for copyright? What if the added notes make the book a sudden hit? Are the notes just a free gift to the original author and other readers? and what if the author of the book hates the notes???