Journalism ethics and social networks

I am leading a seminar in ethics relating to innovation Oct. 10 for the Arizona Newspapers Associaion and the American Press Institute. A new session I am developing for this seminar will cover ethical issues relating to journalists using social networks. I am interested in learning (by email if you don't want to discuss publicly) about difficult ethical situations you have dealt with relating to social networks? What are questions or issues you think I should address in the workshop? What guidelines and boundaries do you follow in your use of social networks? (I will ask this question in two groups: Wired Journalism Ethics and Social Networks.)