The Wall Street Journal’s guidelines advise users to not mix “business and pleasure” in their postings and also warns: “Sharing your personal opinions, as well as expressing partisan political views, whether on Dow Jones sites or on the larger Web, could open us to criticism that we have biases and could make a reporter ineligible to cover topics in the future for Dow Jones.
An excellent caution, albeit from the “old school” of journalism ethics. Personally, I think it is just such ethics that define professional journalism and that are expected from anyone society would value for being a professional journalist.