There were already workarounds in place before they switched off SA - the introduced error was consistent within a given area, so provided you had a fixed location that broadcast its coordinates, you could correct for the error. I believe there were products and possibly even standards that did all of this; would have been even easier in today's world of mobile internet. I have suspicions that this was a large reason for disabling SA - your enemy can work around it, so it's not much use, but if you get your enemy hooked on it without the work-around, you can turn SA back on in a war situation.