Signal Jammer

The Signal Jammer is an item that can be purchased at the store for 2,000 gems or traded. It is not available through seed splicing.

The Signal Jammer jams the name of your world when you broadcast something, or do a msg; coming up with JAMMED! where it should say the name of your world. The Signal Jammer also makes your world not come up on the select world screen, no matter how many people are currently in it.

In-game description: 

When activated (punch to activate), this prevents your world from being listed on the World Select screen.

Signal Jammers automatically return to your inventory once broken

People can only join the world where the Jammer is located if they know the name.

When placed, (if you have not placed a World Lock before), you can get the "This land is my land!" achievement.

Store Info:

Get off the grid! Install a Signal Jammer! A single punch will cause it to whir to life, tireless hiding your world and its population from pesky snoopers - only those who know the world name will be able to enter. It's a perma-Item, it's never lost when destroyed'.

A Signal Jammer in the store.

A Signal Jammer turned off.