There's just too many backdoors in smart phones. That's why I choose to use standalone hardware that can work with any phone for my voice encryption project: http://techcrunch.com/2014/07/31/jackpair/
I don't think I see the relevance. This article isn't about spying on you, it is about disabling your phone remotely ("kill switch," etc). How does encrypting your voice before it enters your phone mitigate that? Plus if you're paranoid enough to use that then frankly you're too paranoid to own a cellphone at all. They can still use it to track your location and to remotely turn on the microphone and eavesdrop on the…
That said, a law that explicitly gives the state authority to shut down all cell phones in a situation "they perceive" as a risk is an order of magnitude worse.
(The "kill switch" counterpart to JackPair would be systems like mesh networks, ham radio / APRS, etc. GoTenna is one recent commercial product: http://gotenna.com/ Of course it can probably be easily jammed)