I'm more surprised that Russia or China haven't attempted to communicate with things like Voyager. Not necessarily to sabotage, but to find out as much as they can about it by interacting with it.
At the time? Perhaps, I don't know when the design documents* became public.
But today, Voyager 1 is a 50 year old curiosity, still of interest to cosmologists of course, but governments will be less interested in it than archeologists.