Cell phone jammer c 50 - cell phone jammer Pinckney
Recently North Korea developed innovative military model of GPS jammer with unbelievable jamming range of 100 kilometers. It makes GPS tracking in the working area of the jammer completely useless. This jammer blocks all GPS frequencies with extremely powerful signal and there is no GPS system that can resist it.
So yes, US plane RC-7B ARL was forced to land because its GPS navigation was totally disabled and there was a risk of loosing controls and crashing if not land in time. This example shows that GPS jammers are quite effective and when they are powerful enough they can become great tool to use.
But let us get back to the problems of common life, which are also may be connected to the GPS technology. If they will appear in your life in any form (like GPS trackers, for example) you can use GPS jammers to protect yourself from their harmful activity. They are not as powerful as North Korean GPS jammer, but I guess you would not need 100 km of jamming radius? wouldn’t you? :)