Open Access (OA) is good for science, good for the library, good for authors. However, a world of pseudo-journals, sometimes labeled “predatory journals” with nice sounding titles like Global Journal of Medicine and Public Health or American Journal of Social Issues and Humanities, but they are often sham titles. Their major purpose is to collect the author fees, and their content lacks quality. Often they list editorial boards consisting of non-existent people or include scholars on an editorial board without their knowledge or permission. Sometimes they use made-up impact measures (such as “view factor”).
The Scholarly Open Access blog maintains a list of individual journal titles that meet their criteria for determining predatory open-access publishers. It is recommended that you not accept an offer to be on their editorial board, nor pay their author fees to publish in one of these titles! In the most concise terms, if you’ve never heard of the journal, best to avoid it.
Much has been written on this, including articles in The New York Times, Nature, and The Scholarly Kitchen blog.