In previous work, we have introduced the data environment as a powerful explanatory concept in the realm of data privacy, with specific regard to the concepts of anonymisation and statistical disclosure. Here, we explain the concept more fully and examine how the socio technical system, that is titled social media, embodies and transforms the social data environment. We draw on both a social philosophy and sociological framework, but populate that framework with both agents and artefacts. We argue, that the data environment concept is an important organising principal, which has implications in epistemology and ontology, and for how we understand notions like disclosure, identity, society and perhaps most critically, privacy.