The article says it is illegal in the USA, but seems the NOTAMs issued by the FAA say the USA is doing it too. I know Fallon, NV, Area 51 at Goose Lake, NV, and Ridgecrest, CA Naval Weapons Station have been part of the NOTAMs here on GPS matters. I think there was one on the east coast someplace too, likely a military installation. If commercial pilots encountered GPS issues or if it is off for the times in the NOTAM, they could request radar vectoring out of ATC and/or use VORs. Interesting part is where they can affect the signal at certain altitudes.