The ability to access and disseminate information through digital communication networks (e.g. internet, mobile phones) is affecting societal activities including national and local politics [1, 2], accountability [3] and health care [4]. Changes in health provision receive attention on social media such as Twitter [5]. In the health area, lay-controlled networked groups, such as mothers of young children and people with rare diseases, are becoming powerful, special-interest, political lobby groups. However, this phenomenon is not replicated across all health issues, population groups and contexts [4]. In this scoping study we are focusing on networks using digital communication and controlled by lay people, that is, people who are not part of formal health care systems but may be interested in health for themselves or on behalf of other people including society more generally. The networking related to health may be within a wider social networking context such as ‘Mumsnet’ [6] where health issues come and go. We suggest that it is important to understand the impact on health and the health care system of these lay-controlled networked groups, and how and why their effects vary.