First, you couldn’t trust houseplants & potato chip bags.
But that’s not what’s going to do you in.
No, you’re doomed because of your super-fancy smart phone.
Not from the microphone or the GPS (although that’s not doing you any favors, privacy-wise), it’s the phone’s gyroscope, which automatically rotates the screen when you rotate the phone – it lets anybody eavesdrop on you [emphasis mine]:
The MEMS gyroscopes found on modern smart phones are sufficiently sensitive to measure acoustic signals in the vicinity of the phone. The resulting signals contain only very low-frequency information (< 200 Hz). Nevertheless we show, using signal processing and machine learning, that this information is sufficient to identify speaker information and even parse speech.
***Since iOS and Android require no special permissions to access the gyro, our results show that apps and active web content that cannot access the microphone can nevertheless eavesdrop on speech in the vicinity of the phone.***
This sort of thing is why I have a superunfancy blitheringidiotphone.
Oh, and at the link, you can also scroll down to find out what else that stalkerment officials don’t need permission to access.
If you need me, I’ll be over here under my tinfoil tent…