The government is paranoid about maintaining control.
Then facilities that want to disallow recording only have to purchase a small transmitter to provide the required disabling signal.That's a little dicier a proposition if the disabling mechanism isn't built into the device itself. And I can't see Google willingly doing that without legislation forcing it to do so.
Recording devices in large numbers could very easily be pitched as a threat to national security, because lets face it the government won't be able to get away with anything if everyone who sees it can record it and show footage online. That police abuse is just the tip of the iceberg. False flags? Government inside jobs? Top secret technology? Even just possible political scandals. If they can keep it covered up just by pushing a button on the dash of the cop car, why wouldn't they.
Simply mandating that when devices are exposed to a certain transmission pattern on a certain frequency results in disabling their recording capabilities would be an easy way for them to continue to keep people ignorant. Officials then merely need to make sure these signals are being transmitted while on official functions to prevent them from being recorded, except by authorized equipment for government use only that has the option to override the shutdown signal.
It would be no more questionable than gun control, and far less difficult to implement since the consumer hardware industry would happily lobby in favor of a bill that allows them to sell small transmitters styled similar to wifi hotspots intended to provide this signal for facilities that do not allow recording equipment.