To date, most measurements of the debris population have been carried out in the LEO and GEO-GTO regions, using radars and optical sensors, respectively. The remaining orbital space (which includes MEO) has been sampled only minimally. Given the size of the MEO population and the typical mechanisms for on-orbit fragmentation it is statistically likely that there exists in MEO a debris population with a similar payload-to-debris ratio as for other high Earth orbits such as GEO. This paper reviews the reasons for the poor coverage of MEO, discusses the utility of surveying (cf. tracking) and sensor cueing for the surveillance of space, and reports on a MEO debris observation campaign.