Taking advantage of the same phenomenon that allows us to see the sky as blue, Distributed Acoustic sensing (DAS) is the most novel technique for safe and efficient pipeline monitoring. DAS offers the possibility of reading the fingerprint of an entire pipeline at the speed of light by using fibre optic cable as spatially distributed sensor elements. Some of its applications include detection and identification of third-party intervention, geohazards and leakages. Furthermore, DAS offers synergies by using the existing telecommunications infrastructure, if the fibre optic cable is laid along the pipeline. This article presents the technical aspects behind DAS and the scenarios where pipeline monitoring can benefit from it, a performance analysis, and a glimpse of DAS as part of a holistic approach to security of critical infrastructure. Finally, a case study is presented on the commissioning of DAS for a gas pipeline.