 The conceptual gaps that exist regarding privacy and the definition of personally identifiable information in the context of big data research inevitably lead to similar gaps regarding when informed consent is necessary. Researchers mining Facebook profile information or public Twitter streams, for example, typically argue that no specific consent is necessary due to the fact the information was publicly available. It remains unknown whether users truly understood the technical conditions under which they made information visible on these social media platforms or if they foresaw their data being harvested for research purposes, rather than just appearing onscreen for fleeting glimpses by their friends and followers (Fiesler &amp; Proferes, 2018). In the case of the Facebook emotional contagion experiment (Kramer, Guillory, &amp; Hancock 2014), the lack of obtaining consent was initially rationalized through the notion that the research appeared to have been carried out under Facebook’s extensive terms of service, whose data use policy, while more than 9,000 words long, does make passing mention to “research”. It was later revealed, however, that the data use policy in effect when the experiment was conducted never mentioned “research” at all (Hill 2014).