Were the lists really the problem though?

Or was it the Genocidal Intent?

The first mass killings, on the Eastern Front, made no use of such sophistication and had no need of it.

It's always Politics.... Terrible ones in the case of WW2 Germany.

By that logic, why bother requiring search warrants? As long as government doesn't have bad intent, it should all be fine.

Yes, the lists where the problem because it is a lot easier to find your victims if you have a list of their addresses.

You‘ll never know when the next group with bad intent get access to surveillance data.

Every crime organization would be glad to have the opportunity to find witnesses in witness protection. Was a lot harder back then.