Recent terrorist attacks in the United States have generated significant attention in many countries to the threats posed by biological weapons. In response to these events and the specter of future attacks, bioscientists and professional organizations have begun or intensified asking questions about the possible malign applications of their research. Part II of this two-part article examines the emerging responses initiated by biomedical organizations and spokespersons in the US and the UK. In doing so it considers how scientific and medical research communities are defining and policing notions of professionalism, responsibility and accountability in the responses made. Through an examination of these issues, suggested lines for future social analysis are offered.