This reminds me of another idiot device they gave to the British bobby: back in the 70's and 80's, there was a glut of illegal CB sets in England. They never legalised the use of 27MHz AM/SSB CBs and all the units sold were marked 'for export only'
When they legalised CB, units that were approved could only transmit FM. Instead of overworking the radio inspectors, they gave bobbies on the beat a box that detected if a close transmitter was AM or FM, with two LEDs. The only problem was amateur radio operators can legally use AM and SSB (after all, they invented it!). One beat p.c. stopped a ham and asked him to talk in the mike, and, you guessed it, the illegal CB light lit up!
Only when the amateur radio operator started cursing and swearing at the p.c. and getting red in the face did he consult another p.c. over the police radio who was a ham. This being the appropriate behaviour for a ham accused of being a CB'er, he let him go with an apology.