This article develops a systems-theoretical perspective on digital communication in closed communication places, focusing on membership as the central principle structuring communication in non-public settings. It combines the concept of membership-based social systems with the distinction between operational coupling and structural coupling in order to analyze whether communication in membership-gated digital communication places (MDCPs) may become consequential for the mass media system and the political system. Although MDCPs have become part of everyday digital communication, they remain under-theorized, especially with regard to how they affect the interplay between social systems. The article conceptualizes MDCPs as communicative extensions of membership-based social systems and shows how different membership logics shape the selection and circulation of communication. It argues that increasing operational coupling does not condense into stable structural coupling with the mass media system or the political system. This creates asymmetries of observation: communication in MDCPs may become publicly or politically consequential, while the contexts that make it connectable across social systems remain only episodically observable. MDCPs thus matter because they can irritate the mass media system and the political system without becoming continuously observable to them.