On the surface, this book is an excellent field guide to reading the complicated set of signs and logos spraypainted onto New York’s streets and embossed on its manhole covers. But learning to read that writing is only the beginning: Burrington’s real message is that by noticing the physical dependencies that make up the metaphorical “cloud,” you will also notice a few other things: the infrastructure of surveillance, the unequal distribution of technology, the handful of corporations that have had a chokehold on communications networks in New York for a century. This is a fascinating book, not only for what it reveals, but for the inspired approach to tackling an impossibly opaque topic: just look down.