Empty Shell: A ‘shell running the Minimal Maintenance Architecture, as they do when no-one’s currently occupying them. It provides for maintaining autonomous functions, interfacing with the systems of a body hotel, diagnostics, and teleoperation, but little more.
Also, of course, createable in all the traditional and several non-traditional nasty ways by bad people.
(That Power, for example, that conducts research into the nondeterministic, paracausal aspects of the logos by running millions of simulations of the same events on captured mind-states, looking for variations, slowly stripping away fragments to find what makes the difference, until there’s not much more than one of these left. They may call its simulation spaces “death cubes”, but they’re really “helplessly wishing for death cubes”…
…fortunately, it’s an urban legend.