A characteristic feature of the development of health-related social networks is the emergence of internet-based virtual communities, composed of patients. These communities go beyond the mere interchange of information concerning their conditions, intervening in the planning and execution of clinical research, including randomised controlled trials, in collaboration with health professionals. That was the case, in 2009, when patients suffering amyotrophic lateral sclerosis, a rare and severe disease, conducted a clinical trial in USA, organising themselves through an online platform. This initiative launched a new model for the planning and conduction of clinical research: "Participants-Led Research" (PLR). The distinctive particularities of this new research paradigm represent a challenge to the traditional standards used for judging the ethical soundness of clinical investigation. That is the case, for example, of informed consent. This article aims at identifying the ethical, legal, and social issues (ELSI) posed by PLR and the relevant concepts that may help in solving them. The following issues, in particular, are analysed, that may give place to a new social contract for the ethical assessment of clinical research: consent for participating in research and personal integrity; data protection and confidentiality; benefits sharing and intellectual property.