Roll in the Tanks! Measuring Left-wing Extremism on Reddit at Scale

Social media's role in the spread and evolution of extremism is a focus of intense study. Online extremists have been involved in the spread of online hate, mis- and disinformation, and real-world violence. However, most existing work has focuses on right-wing extremism. In this paper, we perform a first of its kind large-scale measurement study exploring left-wing extremism. We focus on "tankies," a left-wing community that first arose in the 1950s in support of hardline actions of the USSR and has evolved to support what they call "Actually Existing Socialist" countries, e.g., CCP-run China, the USSR, and North Korea. We collect and analyze 1.3M posts from 53K authors from tankie subreddits, and explore the position of tankies within the broader far-left community on Reddit. Among other things, we find that tankies are clearly on the periphery of the larger far-left community. When examining the contents of posts, we find misalignments and conceptual homomorphisms that confirm the description of tankies in the theoretical work. We also discover that tankies focus more on state-level political events rather than social issues. Our findings provide empirical evidence of the distinct positioning and discourse of left-wing extremist groups on social media.