This paper presents a short reliability analysis of the passive and device-free human positioning system called TileTrack. The presented tracking system is fully unobtrusive and requires the user to neither to wear any tags nor to perform any special action, such as talk, to be tracked. Thus, it promotes the concept of calm technology by pushing the sensing actions to the background. The system uses capacitive measurements to determine the placement of feet on different transmitting floor segments. The system's reliability and capability to track moving humans was tested in a real apartment, and the test results are presented as well as analyzed in this paper.