The most important ethical issues in the use of the Internet and World Wide Web in scientific research are considered together with some of the conceptual problems that arise as a result of applying new information technologies to old institutions. The paper concentrates on a set of issues relating to moral responsibility for the production, utilization and diffusion of scientific knowledge in a networked environment. A conclusion is that reliability of information and hence the individual scientist's capacity to take full moral responsibility may be compromised by the environment provided by the World Wide Web.