I hate plagiarism, perhaps more than any other minor sin. It's worse than piracy. Pirates merely make illegal copies, but the end user still knows who is the creator of the work. Plagiarists take credit for work someone else has done, usurping the crown of achievement. I am always very careful to give credit for good ideas and good work where it is due, partly for reasons of self-interest: I want to receive that credit when I am the one who's done a good job.
But to attempt to pull off the kind of plagiarism this Harvard sophomore was trying? Did she think people would actually buy her story that it done was "unconciously"? To the point that she was able to remember large passages verbatim, or nearly so? She should be expelled and a portion of the sales of her book should go to the author whose work was lifted.