Locked permissions

Here's an idea of a locked permission. If the default permissions is set to "locked" with a yellow padlock permission. If they're padlocked, they are temporary, but infinitely half invisible, and not targeted by any mobs. All permissions are disabled while padlocked, and they can't be padlocked again unless the cheats are on. If unlocked, they return to spawn and can't have the Spectating effects.

This prevents griefers from using creepers to blow stuff up. 

Padlocked Players: will need "adventure" permission to be deactivated.

• Can't pick anything up, including XP orbs
• Can't be hurt nor seen by anything. Not even a falling anvil nor potion, but suffocating teleports up to surface.
• Can't have potion effects, but can pause the effect.
• Can inspect if Open containers are enabled.
• Can't be solid to doors if Use doors are enabled.
• Can't block what players are building 
• Can fly if friends with the host.

There's a lot of things.