"These publishers are predatory because their mission is not to promote, preserve, and make available scholarship; instead, their mission is to exploit the author-pays, Open-Access model for their own profit.” (Beall, 2010)
"Journals exploiting gold open access, providing no or non-sensible peer review, undercutting standard article processing charges, while frequently publishing rubbish" (Beall, 2012)
Beall, J. (2010). “Predatory” open-access scholarly publishers. The Charleston Advisor, 11(4), 10-17.
Beall, J. (2012). Predatory publishers are corrupting open access. Nature, 489(7415), 179-180.