The important thing to note is that you don’t have to do anything on this screen to hard-lock your device — once you’ve gotten to this screen, the device is already hard-locked and will require the passcode to unlock. You can’t use Face ID or Touch ID again until the passcode has been entered. This is important because it means you can easily hard-lock your iPhone without even looking at it, or removing it from your pocket or purse. That you can do this surreptitiously is very much by design.
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Just press and hold the buttons on both sides. Remember that. Try it now. Don’t just memorize it, internalize it, so that you’ll be able to do it without much thought while under duress, like if you’re confronted by a police officer. Remember to do this every time you’re separated from your phone, like when going through the magnetometer at any security checkpoint, especially airports. As soon as you see a metal detector ahead of you, you should think, “Hard-lock my iPhone”.
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I find the press-and-hold method easier to remember. I think of it as squeezing my iPhone for a moment to protect its contents.
A hidden but very useful design in iOS.
6/9/2022