Because GPS can be utilized as a poor mans navigational guide for weapons its always been understood that just prior to a war the US is going to be in, our GPS signals will be scrambled. This so that our military has the coding to use our satellites but no one else does. That means domestic users also.

Most GPS cell phone and other current systems also use the Russian GPS, which may not have been shut off and hence your less accurate reading.

Then again its probably just your equipment.

However, if you experience an extremely bright flash of light, don't walk to a window to check it out.