Habit, sorry: I am trying to avoid an overly literal (but admittedly wildly implausible) reading that suggests that setting the proxy is the only thing that can be done once to it: I always try to locate "only" as closely as possible to its target to avoid mistakes like, "I can only feel awake when the sun is up" which rather implies that I can't do anything other than feel awake when the sun is up, where I should have written, "I can feel awake only when the sun is up". My brain may have been scarred by first-order logic and NLP courses such that I can't read like normal people any more! A quick google has http://www.getitwriteonline.com/archive/070901Only.htm explain.