Another iPhone bug, or how to use an iPhone and a sim card with an unknown PIN-code.

Do you think it is possible to turn off the iPhone and not to enter the PIN code when it is turned on again? Naturally, we are talking about a SIM card with a PIN-code protection (it can be removed). It turned out that you can ...
Today I discovered that when you turn off the iPhone by long pressing Home and Power, when you re-enable the PIN, it is NOT necessary to enter the PIN code!
IMHO a serious security bug!