International calls for registering all trials involving humans and for sharing the results, and sometimes also the raw data and the trial protocols, have increased in recent years. Such calls have come, for example, from the Organization for Economic Cooperation and Development (OECD), the World Health Organization (WHO), the US National Institutes of Heath, the US Congress, the European Commission, the European ombudsman, journal editors, The Cochrane Collaboration, and several funders, for example the UK Medical Research Council, the Wellcome Trust, the Bill and Melinda Gates Foundation and the Hewlett Foundation. Calls for data sharing have mostly been restricted to publicly-funded research, but I argue that the distinction between publicly-funded and industry-funded research is an artificial and irrelevant one, as the interests of the patients must override commercial interests. I also argue why it is a moral imperative to render all results from all trials involving humans, also healthy volunteers, publicly available. Respect for trial participants who often run a personal and unknown risk by participating in trials requires that they--and therefore also the society at large that they represent--be seen as the ultimate owners of trial data. Data sharing would lead to tremendous benefits for patients, progress in science, and rational use of healthcare resources based on evidence we can trust. The harmful consequences are minor compared to the benefits. It has been amply documented that the current situation, with selective reporting of favorable research and biased data analyses being the norm rather than the exception, is harmful to patients and has led to the death of tens of thousands of patients that could have been avoided. National and supranational legislation is needed to make data sharing happen as guidelines and other voluntary agreements do not work. I propose the contents of such legislation and of appropriate sanctions to hold accountable those who refuse to share their data.