Potentially not that simple, as there are fundamental limits on the information capacity of a MIMO system, based on the surface area of the volume occupied by the antenna array (in wavelengths squared). The capacity limits apply whether you use the array for communications or radar, as both are governed by Information Theory.
Not to say that it can't be done, but the maths exists to definitively prove whether it can be, so no need for speculation and tinfoil. My gut feeling is that you could scan a small volume from afar, but not a whole block. No, I haven't done the maths.