Mental health check requirement to own guns???

[gym]

This is just basic common sense. When anyone compiles a list, and you don't have the only copy locked in your safe, no one knows where it can end up.
Why argue about suppositions, we don't know who will come into office and demand to see that list, or what might happen to it next week or next year.

 

[Ed Ames]

One of the basic ironies of sigint is that use of information is a form of disclosure. If you compile and use a list, you do not have the only copy no matter how dilligently you keep it locked away. Everyone has heard stories of nations allowing an enemy to kill their citizens in order to avoid showing that they had information about enemy plans.

It has been fairly conclusively proved that datasets without what are commonly thought of as personal identity information (name, SSN, address, etc) can be used to identify individuals with high degrees of certainty, so it is not even possible to keep anonymized data without the potential for damaging disclosure if those data are used.