Jeffrey Beall is the author of the important and useful list of predatory open access publishers, available on his Scholarly Open Access blog. Jeffrey reports that there is a concerted effort to discredit him and his work.
To me this just highlights the importance of his work and the complete lack of ethics of those behind this effort. I applaud Jeffrey's service to the open access community, both through his list and through sharing this experience. Thanks, Jeffrey - please keep up the good work!