Over the last years, something called "cloud computing" has become a major theme in computer science and information security. Essentially, it concerns delivering information technology as a service, by enabling the renting of soft-ware, computing power and storage. In this contribution, we give a high-level overview of the issues that the emergence of cloud computing as a paradigm raises, both from a computer science and a philosophical perspective. We discuss 1) the ideal and limitations of encrypted data processing, 2) the necessity of simu-lating physical constraints in virtualised infrastructures, 3) the personal equivalent of cloud computing in the form of outsourced identity, and 4) the possibilities for connecting policy and technic...