-LCD_PRESENCE should be used to detect lid and thus internal display being connected at power on. Use this to disable rails and interfaces going to that connector when possible, to prevent hardware failure from user attempting to hotplug such connectors.
Also it should detect lid being disconnected during OS runtime via ACPI:
If santa rosa or newer just skip directly to softbrick, as they have VBL shorted to VINT with a fuse (ie. they lack control)
Turn off VBL/VCC3P rails via PMIC (PANEL_POWER_ON signal, L_VDD_EN on a chipset)
Turn off ThinkLight rail (KBD_LIGHT_ON)
Emit continuous beep (via EC)
Perform emergency shutdown (via softbrick if possible, as this will require user to remove ALL of the power sources before turning it on again - which is what user should do to begin with when attaching/detaching the lid connector)
This won't help with somebody submerging LED backlit panel in water or hotplugging connector on panel side, as PWM control is right next to backlight positive supply. Such occurrences though have not been observed in the userbase unlike rampant LID/keyboard hotplug.
If done, repeat for every other connector with presence detection and relatively HV (Consult Absolute Maximum ratings of chips on each signal), or when reverse polarity is possible
grub could handle this as well see #736