This week we're focusing on telemetry. Telemetry is a really critical part of ubiquitous computing systems; it's the label for how we collect, transport and store data collected both through sensors and from people. Telemetry supports context building, which can improve the awareness of particular applications. But there are limitations to telemetry too – we have to make sure that what we can measure is a reliable proxy for what we want to understand. We also have to be attuned to the massive privacy implications of mass automated telemetry collection.