Beall's List listed predatory journals and publishers. The Scholarly Open Access website which hosted the list was taken down in January 2017. The author Jeffrey Beall, a librarian from the University of Colorado cited harassment from predatory publishers as the ultimate cause. For the full story of Beall's List see the Wikipedia entry for Jeffrey Beall.
Journal Blacklists
These are a useful check. However, the publicly available lists based on Beall's List may not be up to date. They are best used in conjunction with your own assessment of the journal's credibility. See also the LKS ASE Predatory Journal Checklist.