Quite a number of applications are set to automatically go on-line to do things like check for updates. Sometimes this amounts to no more than presenting me with an ad. Often it's a hassle. I don't like it. I don't want anything on the system to access the internet in any way automatically except the clock. I thought there was a setting somewhere in system preferences to keep this from happening, but I can't find it. Does such a preference exist? Or is there some other way to keep apps from calling home? TIA. Peter