News that Whole Foods CEO John Mackey posted comments under a pseudonym for years on a Yahoo chat – a story initially uncovered by the Wall Street Journal – has sparked some good discussion in the blogosphere and traditional media. The latter have focused mostly on whether Mackey broke any SEC or confidentiality regulations, and the consensus is he did not. But beyond that legal issue there is no question Mackey broke the informal rules of the blogosphere that promote transparency and attribution. Mackey and his PR team have used tortuous logic to try and explain why his posts (including some where he hyped the stock and positioned himself as a fan of the CEO…or himself!) were totally above board and a way to engage in candid conversation. This is a surprising and disappointing turn of events for one of the more progressive and candid CEOs in the country. Though there is no clear rulebook for the Web, Mackey clearly broke one of the most sacrosanct laws of etiquette – be honest about who you are and what you do. File under “Web 2.0 Scandals” beside the Wal-Mart travelling fan imbroglio.