Yeah, I was thinking about that. It couldn't just encrypt on "no signal". On a rooted Pre I have, I'm able to get lots of radio stuff even when the phone is say

Yeah, I was thinking about that. It couldn't just encrypt on "no signal". On a rooted Pre I have, I'm able to get lots of radio stuff even when the phone is saying "no signal" and I can't make calls. The noise floor is a pretty good place to start. I'm thinking just monitoring the noise and watching for very sudden changes. If you suddenly change rapidly to very quiet, you might be in a faraday bag. Hmm. It actually can only report the SNR. I'll have to look into how it comes up with this number. Thanks for the microwave tip. Might be handy.