The datafication of communication brought about by digitalisation has dissolved Bobbio's ‘great public–private dichotomy’ into a continuum. The idea of a private–public communication continuum materialised by the internet is of course not new, having already been introduced by Bentham long ago. The growing permeability between the private and public spheres has also significantly contributed to the emergence of newspapers and was crucial for the formation and conceptualisation of the public and public opinion. Newspapers were created by supplementing news about public events with business news from private sources and disseminating it to the public. Much later, the British polymath Tom Harrisson, in his inspiring essay on public opinion (1940), saw the British pub as a place where private opinions emerged as public opinions, a kind of hub that communicatively linked private and public opinions. He was not the first to distinguish public and private opining from each other and to compare them (remember Hegel!), but while the others emphasised only the difference between the two concepts, Harrisson observed how private opinions were transformed into public ones and suggested that public opinions are those parts of private opinions that individuals dare to express in public, an idea used by Noelle-Neumann (1980/1993) without reference to Harrisson for her spiral of silence model of public opinion. The question of the relationship and differences between personal ‘public opinions’ as individuals’ perceptions of ‘the world outside’ (Lippmann 1922/1998, 3), individual published opinions and public opinion as opinion(s) expressed by the public(s) has significantly shaped the course of public-opinion debates in the twentieth century.

The changes in human communication instigated by the internet and digital communication devices have been unprecedented since the invention of writing, with manifold and far-reaching social consequences. They have dramatically transformed the relationship between private and public opinions by blurring the boundary between the private and public spheres, which is fundamental to personal rights and freedoms and to a democratic system. With the internet-based integrated public–private communication networks, for the first time in history, the relationship between privateness and publicness has moved from the conceptual to the material, that is, publicness and privateness are directly linked together inside a single technological platform.