The piercing tool is a specific “key” that is used to insert and remove the captive bead from body jewelry, it acts as a sort of “soft” locking, because any piercing tool can add or remove any captive beads.
Piercing tools act both as locks and keys, they can be used safely without risking to lose the key.
By default, when the piercing tool is used as a HUD object, or worn on the avatar as an accessory, only the wearer can use it. But there is a special configuration notecard inside the piercing tool that can be renamed to change this behavior:
In all cases if the piercing tool is rezzed on the ground (not worn) anyone in close range can use it regardless of the public setting.
Activated mode is represented by a glow, and an “activated” hover text when the object is used as a hud element (HUD elements cannot glow)
When the piercing tool is locked in activated mode, you can click multiple objects in sequence without having to click the piercing tool again between each use. This mode can be disabled by clicking the piercing tool a second time. It will also deactivate itself if attached/rezzed or after 30 minutes.