Without actually knowing the infrastructure and policies of the systems, a lot of you obviously experienced techies and smart guys can only speculate
. It all just depends....
I was a systems programmer, systems designer, communications guy before for some large corps that were simply excellent in this type of stuff...they had to be.
Once mined some critical data (a much smaller needle, in a much larger haystack than this). It's potentially doable, but certainly not easy imo...assuming blah, blah, blah