There is a way to lock your windows in an open position at various opening levels, i.e. 4" opening to prevent children from falling out of an open window, 6" to allow more air in the house but sill prevent someone from easily opening the window more to gain access to your house. I know this because I invented the wind-o-lock (TM) window locking system and we are a local Minnesota company... I enjoy leaving my windows open at night a little for the night breeze, and do not worry about intruders. Sure if they want to get in they can, but intruders prefer an easy access point versus one that is locked. Just in case someone ask about how long it takes to remove the lock to leave a house on fire, the lock may be removed in less than four seconds (NY laws require less than 10 seconds).