[The Glyphstone]

I don't see the Tau being so overtly Big-Brotherish either, that's the way the Imperium does it. If Gue'Vesa Bob murders someone, he doesn't become an Unperson, it's openly stated that Bob proved to be an unfortunate social deviant who's been sent for re-education to restore his psychological health, possibly indefinitely. Gue'Vesa Jane isn't overtly punished for her inquiry, and only if she questions the official record is she punished covertly - remember they want to present the 'helping hand' imagery to the people they've already converted, as well as prospects.