Less than 20 years after appearing in the groves of academy, predatory conferences now outnumber legitimate congresses held by scholarly societies. Today, one can attend multiple predatory conferences every month of the year in nearly any major city, from Tokyo to Toronto and Sydney to Helsinki. Competition between predatory companies has become so 31 that even smaller cities have become targets. The sheer number of predatory conferences, sometimes called questionable conferences, combined with the increasing sophistication of the organizing companies, means any unknown conference should be viewed as predatory until 32 otherwise. Some predatory organizers started out as predatory publishers and expanded into conferences. Others focus exclusively on conference organizing, although they may also 33 papers to predatory publishers. The main reason predatory conferences have become such a big problem is that researchers and institutions are doing basically nothing to address the problem. Researchers in countries or fields that place emphasis on conference presentations even purposely use predatory conferences to 34 their CVs to win university jobs and promotions. Many academics, in addition, think predatory conferences are not worth worrying about, especially if their research field places less importance on conference presentations and proceedings publications compared to journal publications. 35 , predatory conferences do threaten the foundations of the ivory tower. Lacking real peer review, they allow anyone to present and publish poor, plagiarized or phony research. Furthermore, as predatory conference organizers have grown, they have been buying legitimate publishers and conference organizers, blurring the line between predatory and legitimate.