One day, you may find yourself in an emergency situation where you need to undo the chain lock of your home's front door, or somebody else's front door. Maybe someone forgot the unlock it when exiting the back door. Maybe you're grandfather is having a heart attack. Maybe your wife is cheating on you. Whatever the reason, it's fairly simple to break in by undoing the chain lock.
Important note: You must have the key to the door in order to get to the chain lock. Someone could also leave the door unlocked (but still chained) or open it for you while still chained. But this information is NOT for criminal purposes.
Sure, you could kick the door and rip the chain lock right out of the wall, but if you're not looking for a destructive method, then Nextraker has the technique for you. All you need for this door hack is some kind of string-like material, like string, yarn, dental floss, fishing line, ribbon, shoelaces, etc.