Purpose Whistle-blowing, which has become an integral part of the post-publication peer-review movement, is being fortified by social media. Anonymous commenting on blogs as well as Tweets about suspicions of academic misconduct can spread quickly on social media sites like Twitter. The purpose of this paper is to examine two cases to expand the discussion about how complex post-publication peer review is and to contextualize the use of social media within this movement. Design/methodology/approach This paper examines a Twitter-based exchange between (...) an established pseudonymous blogger and science critic, Neuroskeptic, and Elizabeth Wager, the former COPE Chair, within a wider discussion of the use of social media in post-publication peer review. The paper also discusses false claims made on Twitter by another science watchdog, Leonid Schneider. The policies of 15 publishers related to anonymous or pseudonymous whistle-blowing are examined. Findings Four issues in the Neuroskeptic–Wager case were debated: the solicitation by Wager to publish in RIPR; the use of commercial software by Neuroskeptic to make anonymous reports to journals; the links between “publication ethics” leaders and whistle-blowers or pseudonymous identities; the issues of transparency and possible hidden conflicts of interest. Only one publisher out of 15 scientific publishers examined claimed in its official ethical guidelines that anonymous reports should be investigated in the same way as named reports, while three publishers referred to the COPE guidelines. Originality/value No such Twitter-based case has yet been examined in detail in the publishing ethics literature. (shrink)