> What stops someone breaking glass or a panel and reaching through and unlocking to get in quickly if you can open without a key? I suppose this can be avoide

> What stops someone breaking glass or a panel and reaching through and unlocking to get in quickly if you can open without a key? I suppose this can be avoided by not having any windows close enough to your doorknob that you could reach the lock from them. But people could just break a window and climb through into your house, anyway.