I'm pretty sure I saw this spelled out years ago in a groups.google.com post, but the amnesiac search engines of today are not yielding it up to me.
I did find these articles:
https://jacquesmattheij.com/if-you-have-nothing-to-hide/
https://medium.com/@hansdezwart/during-world-war-ii-we-did-h...
And one of them references http://web.archive.org/web/20150812120743/https://stadsarchi... (archive link, site is no longer up).