The trick here is to have as _few_ places as possible where that data is operating in the clear as possible, and try to provide as much isolation across them wh

The trick here is to have as _few_ places as possible where that data is operating in the clear as possible, and try to provide as much isolation across them where feasible or where concerns are naturally separated. The problem is that few think like this, except in a few special industries where they live and die by not getting this wrong. Ease of use and whatever gets things working fastest is generally the name of the game (and I don't blame businesses for this attitude, the market punishes anyone who is too careful or slow-moving in almost every industry)