Janet D. Stemwedel's blog had a link to this article in the New York Times by Karen W. Arenson: "Amid Cheating Allegations, Columbia Class Picks Up Pens." NYT December 3, 2006. Unfortunately, it is no longer available free, at least not to me, although I am registered sigh.
Anyway, in a nutshell: The teacher of an ethics in journalism class gave an open-book, take-home, computer-administrated exam. Inside of 30 hours the students had to log on for 90 minutes and take the test. An anonymous source let the teacher know that someone logged on early and was offering info about the test to other students.
The teacher reacted by making everyone write an essay about what they would do if they were editor at a paper and there was an allegation that some not specified author was fabricating his or her stories.
This is a hard problem - you hear of misconduct, but you have no concrete evidence of who did exactly what. This teacher made a learning experience for the entire class out of the situation (and not just collective punishment). I think this is the way we need to go in many cases of plagiarism and unethical conduct: discuss why this is not okay with the students, have them explore the topic themselves.