One example I've had in the past: Inside governments, there are often individual pieces of data within a larger dataset that are protectively marked. For exam

One example I've had in the past: Inside governments, there are often individual pieces of data within a larger dataset that are protectively marked. For example, fake identities created by the government, identities of prominent people (like members of the Royal family) or maybe even people at high risk of identity theft like bank managers. Your normal app just thinks the records for these people are missing or knows that they are present but can't access all of the data for them. These people have to make special arrangements to eg, apply for a driving licence. The way it works in paper processes is that normal caseworkers will get the file and see that it's protectively marked and then hand over to a caseworker who has security clearance. Obviously it depends on how much of your problem domain you're reifying in your database but it can be a nice option, particularly as part of defence-in-depth.