Humanity entered the twenty-first century with revolutionary achievements in biomedical research. At the same time multiple "dual-use" results have been published. The battle against infectious diseases is meeting new challenges, with newly emerging and re-emerging infections. Both natural disaster epidemics, such as SARS, avian influenza, haemorrhagic fevers, XDR and MDR tuberculosis and many others, and the possibility of intentional mis-use, such as letters containing anthrax spores in USA, 2001, have raised awareness of the real threats. Many great men, including Goethe, Spinoza, J.B. Shaw, Fr. Engels, J.F. Kennedy and others, have recognized that liberty is also a responsibility. That is why the liberty to decide now represents an acknowledged necessity: biomedical research should be supported, conducted and published with appropriate measures to prevent potential "dual use". Biomedical scientists should work according to the ethical principles of their Code of Conduct, an analogue of Hippocrates Oath of doctors; and they should inform government, society and their juniors about the problem. National science consulting boards of experts should be created to prepare guidelines and control the problem at state level. An international board should develop minimum standards to be applicable by each country. Bio-preparedness is considered another key-measure.