Plagiarism and Cheating

In my high school English classes, there was a day or two dedicated to learning how to cite other author's work. We were taught, “better safe than sorry” and therefore cited even the smallest of sentences. Why Kaavya Viswanathan thought that copying another's whole paragraph into her work was okay, is beyond me. A high school student would know better than that. So how could a Harvard level college student, who previously seemed to be well accomplished in writing, not know about plagiarism?
I feel as though this story reminds me of the McDonald's coffee issue. A customer had purchased a hot coffee, placed it in between his or her legs, spilled it while driving, and then proceeded to sue McDonald's for not having the, “Caution: HOT” sign on the cup. How ridiculous is that?
Anyway, whether Viswanathan's act was conscious or unconscious, a women of her knowledge should be aware of the rules of plagiarism to begin with. Each syllabus that I have received here at West Chester so far, have all clearly stated that plagiarism will not be tolerated. The writing classes even have a Reference Book that indicates how citation should be correctly done, in order to eliminate the chance for plagiarism. Yet this story does bring up the issue of what exactly is plagiarism and what are its limits? Discussion about plagiarism should definitely take place within each writing class, and even a non writing class that simply requires writing.
Romance novels and movies are well known for either tragedy or a happily ever after theme, that those ideas are universal. If one were to create a book or movie based upon that idea, it is not exactly plagiarism. However, our Text Messaging book gives an excellent example about Harry Potter. How many books and movies, other than J.K. Rowling's, are there about wizards? The same plotted story or movie from another author would obviously be taking Rowling's idea. Personally, I think that is plagiarism at its least, even if the character's names and plot scenes where all different. It has actually been done already. The Disney Chanel plays a show called, “Wizards of Waverly Place”, much like the Harry Potter series, but appropriate for younger children.
Basically, I believe that each school should clearly state it's feelings on the idea of plagiarism, and make it well known what is acceptable, what is not, and how to handle it.