Is this really that hard to imagine? I am willing to bet that there are teams of spies who have infiltrated Google, Facebook, Amazon, etc. Spies from US, Russia, China, Britain, Israel, Germany, etc, must have dozens of spies working as engineers are getting access to all that data as we speak. To think that they aren't would be rather naive, in my opinion. If I were head of the spy agencies in any one of those count…
(I've never actually bothered interviewing with any of the above, maybe it's all entirely normal or you need to write your own self-balancing tree implementation regularly).