None of these always-on systems track every word you say,
because this would run your battery dry in no time. They all have just a low-power minimal voice-recognition in hardware that only recognizes the keywords and only then wake up and hand over control to the SoC itself for what you're actually saying.
Keywords like "Hey, Siri", or "OK, Google". Or "bomb" or "overthrow" or "cocaine" or...
Besides, if Big Brother wants to listen to your microphone he can just do that anyway, no need for such tricks. If you don't trust your networked microphone containing device not to listen to you, don't carry it to begin with. This is true for every fucking phone or tablet or computer.
Quite right. But, even though they can key up the microphone at any time, they don't know when it's interesting to do so. That's where the keyword recognition comes in. Say the secret phrase and it surreptitiously sends a few seconds of audio to the NSA who can then decide whether or not to add you to the list of listening targets.
Okay, I say it like it's a done deal, and even I don't believe that they're doing it yet. But it'd be possible, and it allows for previously unheard-of levels of snooping. Without voice recognition it's not feasible because it'd take too much manpower to even spot-check all those microphones. But if you can enlist the aid of the device itself to secretly alert the authorities... Now you're talking! What law enforcement agency wouldn't like to have an informant in every pocket? Make the list of keywords downloadable, too. Get word of an ISIS plot? Load "ISIS" into the keyword list. Whoa, they changed their name to "Totally Without A Terrorism Scheme" this week? Update the list, let the phones alert us when someone talks about TWATS! AMBER alert? Load the kid's name into every phone in the area. Sure you'll have a ton of false positives, but Think Of The Children! Honestly, is it any more ridiculous then sending a text message with a vague description of the kid to every phone in a 100 mile radius?
Sure I'm paranoid. But am I paranoid enough?