Comment by r721 | Hacker News Reader

Comment by r721 | Hacker News Reader

Facebook's explanation:

>Myth: The feature listens to and stores your conversations.

>Fact: Nope, no matter how interesting your conversation, this feature does not store sound or recordings. Facebook isn’t listening to or storing your conversations.

>Here’s how it works: if you choose to turn the feature on, when you write a status update, the app converts any sound into an audio fingerprint on your phone. This fingerprint is sent to our servers to try and match it against our database of audio and TV fingerprints. By design, we do not store fingerprints from your device for any amount of time. And in any event, the fingerprints can’t be reversed into the original audio because they don’t contain enough information.

>Myth: Facebook is always listening using your microphone.

>Fact: Nope, if you choose to turn this feature on, it will only use your microphone (for 15 seconds) when you’re actually writing a status update to try and match music and TV.

http://newsroom.fb.com/news/2014/05/a-new-optional-way-to-sh... (via http://www.computerworld.com/article/2490090/social-media/ba...)

Myth 1: they claim to not store audio or recordings. They could easily store keywords it detects from the mic.

Myth 2: they don't address what happens when you don't turn on the feature.

Edit to add: Overall they might not "listen to the mic" but they might be detecting words based audio data. It's all of matter of how you define things. Maybe to them, listening to the mic means playing an audio feed of the mic to a human being at Facebook, or software analyzing the full audio stream instead of a transformed/condensed view of the audio.

I wonder if it's possible to capture audio through the motion detection sensors? Would a phone lying on a table be able to pick up vibrations caused by someone speaking? Does the OS provide APIs for app developers to access the information ?

With some training, motion sensors can detect what's being typed on a keyboard sharing the same surface.

That's actually still pretty creepy.

That's an explanation for one single feature. They never mention if other code in the app has the ability to snoop on conversations.

Unfortunately we can't do fine grained permissions like that on any common smart phone OS. You'll have to either take their word for it, or decompile the app and make sure they are telling the truth.

challenge accepted

Well, how have you fared with this challenge?

On iOS, the status bar turns red whenever an app uses the microphone. Unless you think they are jailbreaking the phone.

Even if the app is running in the background? Sorry, I don't use iOS

I wonder if anyone makes a phone with LEDs for all hardware functions, like some laptops have LEDs which light up whenever anything accesses the built-in webcam?

That would be interesting. But having a completely modular phone with hardware kill switches would be better imo. That way you can just dismantle it when not in use. Put it back together when going out. Switch the mic on when needed etc.

Well, it categorically denies that "Facebook is always listening using your microphone," regardless of which feature we're talking about.

But that's also really easy phrasing to write a loophole for :P

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