Should I blow our secret work blogger's cover?

Work ethics is a fortnightly feature in Guardian Work where a reader submits a workplace dilemma and asks for your help. A selection of the best answers will appear in Saturday's paper. (And if you have a dilemma you'd like to share, anonymously, with our readers, please email us.) This week's question I've discovered an 'anonymous' work blog which I'm sure is all about our office. Events match up uncannily and while no one's identified, people have been given recognisably rude nicknames. I'm pretty sure I know who's behind it, but I haven't made it public yet. How should I handle this? What are your thoughts?