Social media and the data it produces lend itself to being visualised as a network. Individual Twitter users can be represented as nodes and retweeted by another Twitter user, thereby forming a relationship, an edge, between users. However, an unbounded network is a sprawling mass of nodes and edges. Boundary settings are typically applied, for example, a time period, a hashtag, a keyword search or a network substructure of a phenomenon of interest. Thus, the particular visualisation created is dependent upon the boundaries applied, enabling productive visual consumption, but concealing its social shaping. To explore this question of boundary setting and its associated issues, we draw on an example from the Twitter discussions about the UK Minister for Health, Jeremy Hunt, and the media debate surrounding the contractual hours of junior doctors during 2015–2016. We discuss the role and impact differing stakeholders have in setting these boundaries. We seek to provide a set of ‘questioning lenses’ in which we ask why these boundary settings were selected, what effect they have, and what are the potential implications of these boundary setting techniques on the visualisation consumer.