The world setting... makes the user invisible to people's eyes... so they can secretly abuse and prank people.
The world setting is where the invisible user... secretly focuses on abusing and pranking people from behind.
Unless the user voluntarily deactivates their invisibility, they will never be discovered by people.

In the world, everyone except the user can never become invisible... only the user... becomes invisible to people's eyes and can act as they please, including secretly abusing and pranking people.