In December 2019 issue of Nature defined predatory publishing:
“Predatory journals and publishers are entities that prioritize self-interest at the expense of scholarship and are characterized by false or misleading information, deviation from best editorial and publication practices, a lack of transparency, and/or the use of aggressive and indiscriminate solicitation practices.” (Grudniewicz et al, 2019)
Deceit is the defining characteristic of academic scams.
Evaluating Scholarly Journals Infographic by Allen Press via FrontMatter (CC BY ND NC 3.0)
Hijacked journals, also known as cloned journals, impersonate legitimate journals by adopting their titles, ISSNs, and other metadata. Occasionally, a Predatory Publisher will acquire a legitimate journal and continue publication without clearly notifying the authors and readers of the change in ownership. Retraction Watch, in collaboration with Anna Abalkina have developed a hijacked journal checker.
Paper mills are the systematic production of fake manuscripts, often plagiarized or written with automatic systems like generative AI LLMs. Authorships in these manuscripts are sold to researchers.
For additional information on how papermills function see: R.A.K. Richardson, S.S. Hong, J.A. Byrne, T. Stoeger, & L.A.N. Amaral, The entities enabling scientific fraud at scale are large, resilient, and growing rapidly, Proc. Natl. Acad. Sci. U.S.A. 122 (32) e2420092122, https://doi.org/10.1073/pnas.2420092122 (2025).