How do a variety of businesses / corporations protect against whistleblowers or possible data leakage points?
To answer this question I would first need to define what a leakage point is. This will help with further research. To answer the question I would start by interviewing a variety of different businesses and corporations. Asking them what type of data they keep and what they define as the biggest threats to it. Do they concern whistleblowers and NSA surveillance a problem. What strategies have they implemented to combat these and what priorities do they place on each strategy they have.
I would also use resources that have are available that give strategies for the above problem as extra resources.
Looking at the problem from the other end (the whistleblowers view) will also help in finding why these breaches happen in the first place. Also it can give insight to weaknesses in businesses / corporations strategies they had in place which then can be related to other businesses and corporations strategies.
The underlying goal is to find out what strategies have businesses and corporations implemented and how do they evolve as the data gets more important or mission critical. How is data protection evolving with the evolving technology relative to “mission critical data”.