Not just assembling the dish - you also have to know the ephemeris schedule, bit coding scheme (it changes based on circumstances), packet formats, software infrastructure... In the great scheme of things, my friend, Cuba or Zimbabwe secretly erecting an 80 meter dish just to f--k with a rover on mars isn't really a concern. Even though ESA or China or Japan might conceivably have the theoretical capability to do this... there are other things to worry about.