New Social Gatekeepers
DMT Part 2 - Structural Polarity: Concentration and Fragmentation as a New Paradigm of Attention Economics.
In the past two years I’ve been working on a book on Digital Media Transformation (DMT) as a co-publisher and authored three papers on “Macro Media Transformations”. My theory in a nutshell: The underlying changes in the structure of the Internet are triggered by the emergence of new interfaces and are decisive for digital transformation as a whole.
Unfortunately I must not publish the complete text here as Springer Gabler will do this in July 2022 (in German), but I can disseminate some parts in this Substack newsletter and blog. In fact I have to because otherwise a fast paced development of reality renders my writings obsolete.
The age of mass media is already behind us. The Gutenberg parenthesis closed after the turn of the millennium; Web 2.0 and later also the Social and Mobile Web have shifted the polarity from mass media senders and receivers (without a return channel) to a new polarity of concentration and fragmentation. 
The new centers of gravity are not media corporations but platforms. Their names include Google, Amazon, Facebook, Apple, Microsoft (GAFAM for short), but you may also factor in Alibaba, Baidu, Telegram, Tencent or even Tesla. They concentrate attention with their media services without broadcasting themselves; they are providing back channels, network individual accounts (not always people), fragment the public sphere, and – by use of their social network infrastructures – allow people to build huge audiences. Cristiano Ronaldo, Taylor Swift, Elon Musk  or Donald Trump reach more people than major TV networks or daily newspapers did twenty or thirty years ago.
In German-speaking countries, celebrities from media companies in particular also expanded their megaphones on Twitter - often via the public broadcasters funded by mandatory fees, regardless of their role as news, weather or satire presenters. The fact that reach is capitalized here, paid for with quasi-tax money, may be seen as problematic.
In the study "Structural Polarity - Concentration and Fragmentation as a New Paradigm of the Attention Economy" which is printed in the forthcoming volume "The Digital Transformation of the Media" (Springer Gabler), I devote two paragraphs to this question:
Journalists have a special role as a link between traditional mass media and the social web. Many use their professional position and the associated perception and popularity to realize and manage their potential reach [...] as a personal brand and medium in the social networks. Very often, this blurs the boundaries of professional communication with personal opinion, so that the audience must inevitably come to a new form of joint perception of employer medium and social medium. If, for example, a popular journalist from a daily newspaper or TV anchorman also acts as a social medium, thus leaving the professional sphere in terms of content or enriching professional research in a personal context with her own opinion, then this requires a very high level of concentration and abstraction on the part of the recipients to correctly classify individual tweets or Facebook postings, i.e. to assign them to the professional or personal sender. This mixing or expansion of communicative dispositives can also be desired and intentionally sought by the medium and the journalist.
This raises questions of journalistic ethics, especially when public media in their democratic function is concerned. Is activity of individual accounts (aka person media, identity brands) beyond the requirements of a publicly funded medium and therefore factoring a certain compliance at all permissible? And if so, in what form?  De facto, in such a case, mandatory fees, levies or taxes are used to support identity brands of individuals whose content-related statements beyond the journalistic core area are to be viewed critically in the professional-personal media network per se. The new power of social media thus also establishes person media brands, which already occupy this role in their organizations, as new social gatekeepers within the platforms. These social gatekeepers are leaving the traditional media dispositif and are having a noticeable effect in terms of their filtering function and weighting of content. But they also become more ideologically transparent.
Footnotes & References
 For a detailed explanation, see "Structural Polarity - Concentration and Fragmentation as a New Paradigm of the Attention Economy" in "The Digital Transformation of the Media" (Springer Gabler).
 This week is marked by a special circularity, because Elon Musk - himself one of these person media brands and founder of Tesla - takes over Twitter, a special platform of the attention economy, and thus combines several structural phenomena in one person. (Mark Zuckerberg arguably also has a Facebook profile, but not this impact.) Exactly what this particular convergence of three directions in Elon Musk will mean for the theory requires a bit more thought, which I may develop in a later post.
 The BBC, for example, is always discussing restrictions and policies on the use of journalists' personal accounts. See https://www.horizont.at/medien/news/soziale-medien-bbc-generaldirektor-droht-mitarbeitern-mit-twitter-bann-82511
From Command Line to Metaverse
DMT Part 1 - Macro Media Transformations as the Basis of Digital Media Transformations