Is Citation Extortion practised? asks Peter Murray-Rust, a professor of chemistry at Cambridge University. He writes of a researcher he met who said she had submitted a manuscript and been told by the publisher (or editor) that it would not be published unless she included at least two citations to papers published by that publisher. Professor Murray-Rust is understandably appalled by this report, and asks readers of his blog whether this is a routine experience for them when submitting papers. Certainly this practice does not occur at any journals published by Nature Publishing Group: the citation list is entirely up to the author, although peer-reviewers (who are independent of the journals and of each other) might make suggestions as part of the revision process.