I just watched a YouTube clip by Salomondrin that demonstrates how to easily open a Model X frunk with a screwdriver. It does set off the alarm if the car is locked, but would not prevent someone from grabbing the contents without too much hassle. I assume this feature is to allow frunk access when the 12V battery is dead, but must admit some concern... This may also apply to refreshed model S, but I posted it in the X sub forum given the video demonstration. Skip to 8:40 to get to the relevant bits.