ScienceOpen, which promotes Pluto journals and offers them peer review facilities (among much else), has just requested that Prometheus change its submission system from single-blind peer review to double-blind peer review. This would mean that neither referees nor authors would know the identity of the other. On the face of it, this increased anonymity makes the peer review process fairer and more efficient. The single-blind system long used by Prometheus allows the referee to remain anonymous while knowing the identity of the author. Prometheus is a niche journal and a referee with no idea who had written the paper she was reading (or could not ask Google) was probably insufficiently familiar with the subject to write a decent report. Double-blind peer review seemed only to mask this reality. While double-blind peer review is fashionable in the social sciences and humanities, the sciences generally lean towards single-blind peer review, presumably because they, like Prometheus, value expertise above anonymity.