Recently, the Simon Singh defamation case became a cause celebre in the UK for a push for big changes in defamation law, which might have relevance to our law. However, some aspects of the campaign for change have been misinformed and misdirected. In a number of recent cases in the United Kingdom, professional bodies or companies have sued individuals who have criticised the support given by such bodies for the practices of their members or application of scientific methods. Simon Singh, a science writer, was sued by the British Chiropractic Association for questioning the evidence for its medical claims, and Peter Wilmshurst, a cardiologist, is being sued over his criticisms of an American company’s heart implant trial. A movement has grown up around these cases where concern has arisen about the chilling effects of the law on scientific criticism.