I would use one for privacy but there would be black vans following me around and probably land a felony. It is really easy to track these things. All they have to do is look for big blob of gps unavailable bubble moving around and they can also triangulate the signal with fairly cheap tools. Jamming is just spamming noise after all.
Yes and there was an article few months ago telling that burglars now use wifi jammers to turn off wifi security cameras before breaking and entering. Those jammers are pretty much illegal as well but criminal do illegal stuff anyways…
That being said, how would blocking only the GPS help criminals in their criminal activities? I lack imagination I guess.