‘Once each of the unremarkable acts we undertake in the course of the day—opening the front door, buying the groceries, hopping onto the bus—has been reconceived as a digital transaction, it tends to dematerialize. The separate, dedicated chunks of matter we needed to use in order to accomplish these ends, the house keys and banknotes and bus tokens, are replaced by an invisible modulation of radio waves. And as the infrastructure that receives those waves and translates them into action is built into the ordinary objects and surfaces all around us, the entire interaction tends to disappear from sight, and consequently from thought’ (pp. 10-11).