Minecraft World Lock.

Lets Say that you really don't want a world deleted and your scared that you may one day delete it on accident. There should be an option on the minecraft select world screen were you can choose a world and in the edit menu of that world, one of the options would be weither or not you'd like the world locked or not, you could still go into the world and build stuff and what not, but it would prevent you from accidentaly deleting that  world that is locked. and you could always unlock a world as well. You can tell if a world would be locked or not if a little lock icon would appear next to the title or date and what not.