From The NY Times article, Scientific Articles Accepted (Personal Checks, Too):
Jeffrey Beall, a research librarian at the University of Colorado in Denver, has developed his own blacklist of what he calls “predatory open-access journals.” There were 20 publishers on his list in 2010, and now there are more than 300. He estimates that there are as many as 4,000 predatory journals today, at least 25 percent of the total number of open-access journals.
“It’s almost like the word is out,” he said. “This is easy money, very little work, a low barrier start-up.”
Journals on what has become known as “Beall’s list” generally do not post the fees they charge on their Web sites and may not even inform authors of them until after an article is submitted. They barrage academics with e-mail invitations to submit articles and to be on editorial boards.
Much More About the List in the NY Times Article
Direct to Jeffrey Beall’s Scholarly Open Access Blog
Hat Tip: @mattrweaver