The number of publishers that offer academics, researchers, and postgraduate students the opportunity to publisharticles and book chapters quickly and easily has been growing steadily in recent years. This can be ascribed to avariety of factors, e.g., increasing Internet use, the Open Access movement, academic pressure to publish, and theemergence of publishers with questionable interests that cast doubt on the reliability and the scientific rigor of thearticles they publish.All this has transformed the scholarly and scientific publishing scene and has opened the door to theappearance of journals whose editorial procedures differ from those of legitimate journals. These publishers arecalled predatory, because their manuscript publishing process deviates from the norm (very short publicationtimes, non-existent or low-quality peer-review, surprisingly low rejection rates, etc.).The object of this article is to spell out the editorial practices of these journals to make them easier to spot andthus to alert researchers who are unfamiliar with them. It therefore reviews and highlights the work of otherauthors who have for years been calling attention to how these journals operate, to their unique features andbehaviors, and to the consequences of publishing in them.The most relevant conclusions reached include the scant awareness of the existence of such journals (especiallyby researchers still lacking experience), the enormous harm they cause to authors' reputations, the harm theycause researchers taking part in promotion or professional accreditation procedures, and the feelings of chagrinand helplessness that come from seeing one's work printed in low-quality journals. Future comprehensive researchon why authors decide to submit valuable articles to these journals is also needed.This paper therefore discusses the size of this phenomenon and how to distinguish those journals from ethicaljournals.