What is the ruling on taking soil from the garden of an abandoned house to make a protective barrier against stray bullets, without the owners' knowledge?

It is not permissible for the neighbors of an absent homeowner, nor for anyone else, to take anything from the house or its contents without the owner's permission. This is because the wealth and honor of Muslims are inviolable, and the property of a Muslim is not lawful except with his willing consent. Neighbors are obligated to safeguard their neighbors' homes when they are absent. Their repentance involves seeking forgiveness from the homeowner or returning the dirt that was taken, based on the hadith: "On the hand is what it took until it restores it."