Very good question, here is my 2 cents. In the middle of the night, you hear the glass break. You get out of bed, grab your weapon, don your armor, and engage? Unless you live in Al Gores house, you will have run out of time, and get yourself dead. On the other hand, body armor does make great sense for defense of property if society takes a total dump, and law enforcement is not option. In any case, if I had the option of having/not having protective armor, I'd definitely get it. You would just have to sleep in it for it to be effective for home invasions.