The emergence and growth of a collection of large and global private networks operated by big tech companies like Google, Facebook, or Amazon have thoroughly disrupted the Internet ecosystem. Associated developments have shifted and blurred the lines between public and private networking and contributed to a seismic shift in the topology and industrial organization of the ecosystem. In this paper, we explore the growing complexity and evolution of the Internet ecosystem and analyze the causes, drivers, and implications of fractures and fragmentation in the ecosystem. We adopt a multidisciplinary perspective and synthesize our findings into a typology of different dimensions of fractures and fragmentations. Our findings provide empirically substantiated insights into the complex and evolving web of vertical and horizontal relationships such as collaborations or integration strategies, complementarities, and synergies, as well as altered ownership and governance structures and market positions. The insights gained provide evidence that informs policymaking in various current matters such as network neutrality regulation, data governance and sovereignty, and the regulation of big tech.