 ‘Social networking’ is an inherently ambiguous term requiring some clarification. Human beings have been socially ‘networked’ in one manner or another for as long as we have been on the planet, and we have historically availed ourselves of many successive techniques and instruments for facilitating and maintaining such networks. These include structured social affiliations and institutions such as private and public clubs, lodges and churches as well as communications technologies such as postal and courier systems, telegraphs and telephones. When philosophers speak today, however, of ‘Social Networking and Ethics’, they usually refer more narrowly to the ethical impact of an evolving and loosely defined group of information technologies, most based on or inspired by the ‘Web 2.0’ software standards that emerged in the first decade of the 21st century. While the most widely used social networking services are free, they operate on large platforms that offer a range of related products and services that underpin their business models, from targeted advertising and data licensing to cloud storage and enterprise software. Ethical impacts of social networking services are loosely clustered into three categories – direct impacts of social networking activity itself, indirect impacts associated with the underlying business models that are enabled by such activity, and structural implications of SNS as novel sociopolitical and cultural forces.