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Police seek Amazon Echo data in murder case

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Re: Police seek Amazon Echo data in murder case

#21

Post by ethbro »

amelius wrote: post #10
praseodym wrote: post #6

Earlier quoted context omitted.

Speech can be encoded with less than 10Kbps [1], which means a maximum of 108MB of data per day. I don't think that's an impossible amount of data. [1] e.g. https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_code...

You could even convert it to text before sending.

For NLP research, you'd want something that preserved more information than text.

Questions for anyone in the field: how much is preserved? Is there a text form that allows for iterative testing? Maybe the output of a first-pass pheneme decoder? If so, what kind of space requirements?

Re: Police seek Amazon Echo data in murder case

#22

Post by agentgt »

praseodym wrote: post #6
bkbridge wrote: post #2

Alexa only waits for the wake word "Alexa." It would cost more money than God in hardware to store every thing Alexa ever heard. She saves you're requests. And shows you those request in the Alexa App. And you can also delete it if you wish. There is no data for the police to have, because beyond requests, there is no data. Unless someone knows more about this than Amazon is telling us?

Speech can be encoded with less than 10Kbps [1], which means a maximum of 108MB of data per day. I don't think that's an impossible amount of data. [1] e.g. https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_code...

It is also feasible the device could just wait and transmit only voice like data and drop other sound data... (Even my crummy baby monitor can detect the difference.)

Speaking of which I wonder what the net traffic usage of the Echo is?

Re: Police seek Amazon Echo data in murder case

#23

Post by tyho »

bkbridge wrote: post #2

Alexa only waits for the wake word "Alexa." It would cost more money than God in hardware to store every thing Alexa ever heard. She saves you're requests. And shows you those request in the Alexa App. And you can also delete it if you wish. There is no data for the police to have, because beyond requests, there is no data. Unless someone knows more about this than Amazon is telling us?

> It would cost more money than God in hardware to store every thing Alexa ever heard

About $2.55 / year [0][1][2], or, storing in AWS S3 "Infrequent access storage", about $180 after 5 years of recording [3][4].

[0]: https://www.amazon.com/dp/B00684XVFS/

[1]: https://wiki.xiph.org/Opus_Recommended_Settings#Recommended_...

[2]: https://www.wolframalpha.com/input/?i=0.027+USD%2FGB+*+24+Kb...

[3]: https://aws.amazon.com/s3/pricing/

[4]: https://www.wolframalpha.com/input/?i=(1%2F2)*(0.0125+USD%2F...

Re: Police seek Amazon Echo data in murder case

#24

Post by FrancoDiaz »

Flammy wrote: post #3

I'm curious if the police will push this, as it could reveal how much voice information is actually stored. Amazon has declined to answer how much voice information is stored online[1] and how much if that is tied to your identity. We do know that Alexa stores a list of queries you've spoken, and you can "delete" these records, but it is unknown if this impacts the actual voice data behind them. [1] https://www.amazo…

Wait a minute, we'd already know if Alexa was recording everything by the network traffic that obviously has already been sniffed. We can assume that Amazon is storing every "Alex,..." query that you've ever done. So what is there to know?

Re: Police seek Amazon Echo data in murder case

#25

Post by 9NRtKyP4 »

MiddleEndian wrote: post #9
bkbridge wrote: post #2

Alexa only waits for the wake word "Alexa." It would cost more money than God in hardware to store every thing Alexa ever heard. She saves you're requests. And shows you those request in the Alexa App. And you can also delete it if you wish. There is no data for the police to have, because beyond requests, there is no data. Unless someone knows more about this than Amazon is telling us?

Https://ubrp.arizona.edu/study-finds-no-difference-in-the-amount-men-and-women-talk/ Average man uses 15,669 words/day, woman uses 16,215. Let's say average household has two people and half those words are spoken at home, 31,884/2 = 15,942. Let's say 8 bytes per word on average, just under 128k/day. That's a little under 47 MB/year. Not too expensive. Edited with better source/numbers.

> There has never been any "study" showing that "women talk almost three times as much as men", although this non-existent "research" has been cited by dozens of science writers, relationship counselors, celebrity preachers, and other people in the habit of claiming non-existent authoritative support for their personal impressions;

Re: Police seek Amazon Echo data in murder case

#26

Post by bsharitt »

bkbridge wrote: post #2

Alexa only waits for the wake word "Alexa." It would cost more money than God in hardware to store every thing Alexa ever heard. She saves you're requests. And shows you those request in the Alexa App. And you can also delete it if you wish. There is no data for the police to have, because beyond requests, there is no data. Unless someone knows more about this than Amazon is telling us?

Even if Amazon doesn't store all audio by default now, I would if it could become a thing(if it's not already) for law enforcement to basically get a warrant for Amazon(and Google and everyone else who gets into this space) to store everything and send it to law enforcement for specific individuals.

Re: Police seek Amazon Echo data in murder case

#27

Post by api »

troncheadle wrote: post #15
Flammy wrote: post #4

Earlier quoted context omitted.

> It would cost more money than God in hardware to store every thing Alexa ever heard Depends, first of all storing compressed audio isn't that space-expensive, especially in some long term data storage like s3. Additionally they could only be storing the transcriptions, but not the voice behind them, which would be a lot less data. We don't know as Amazon hasn't been very forthcoming about the privacy aspects of Ale…

> but who knows if the voice data or even the query itself is still stored after deletion, just not visible to us end users. Almost definitely yes. I've never known a tech company that truly deletes anything

"Never really delete" is actually standard advice. There are loads of reasons, mostly non-nefarious, why you may want or need that data.

Sometimes deleted stuff is archived offline or in slow warehouse databases that are not live, etc.

Re: Police seek Amazon Echo data in murder case

#28

Post by Flammy »

FrancoDiaz wrote: post #24
Flammy wrote: post #3

I'm curious if the police will push this, as it could reveal how much voice information is actually stored. Amazon has declined to answer how much voice information is stored online[1] and how much if that is tied to your identity. We do know that Alexa stores a list of queries you've spoken, and you can "delete" these records, but it is unknown if this impacts the actual voice data behind them. [1] https://www.amazo…

Wait a minute, we'd already know if Alexa was recording everything by the network traffic that obviously has already been sniffed. We can assume that Amazon is storing every "Alex,..." query that you've ever done. So what is there to know?

We know they are streaming it to do all the NLP in the cloud. This is obvious from the computational costs alone of doing NLP.

The important question here is "What happens to the audio data streamed to the cloud, a few seconds AFTER the query has been identified (or not identified) and the results sent back to the Alexa device?"

The nieve assumption is "all audio data is deleted after processing". The reality is that data is still valuable to Amazon for a variety of uses such as

(1) further training their voice recognition software

(2) advertising data mining [how many people are in the room, things they are talking about --- note, Facebook's mobile app infamously does this]

If they just store the query text, that is 'best case' from a privacy perspective. If they just store query text and query audio, that is less than ideal, but not too bad. If they store all audio, ever recorded, for an indefinite period of time... that is what this police request could reveal: Audio data stored for a non-keyword-trigger, and for days/weeks after the fact.

Re: Police seek Amazon Echo data in murder case

#29

Post by dannypgh »

cryptarch wrote: post #13
bkbridge wrote: post #2

Alexa only waits for the wake word "Alexa." It would cost more money than God in hardware to store every thing Alexa ever heard. She saves you're requests. And shows you those request in the Alexa App. And you can also delete it if you wish. There is no data for the police to have, because beyond requests, there is no data. Unless someone knows more about this than Amazon is telling us?

It would cost about $30m a year if you tailor the system to flagging specific data for storage and don't naively store every moment (e.g. you scrap silent moments and use VBR encoding). Storing a year's worth of 96kbps audio costs 380GB. If you don't record silence and you assume the people around an Alexa are only speaking for at most 4 hours a day on average, that goes down to 76GB a year. So if you then assume 5m…

I think you're orders of magnitude off in marginal cost estimates for glacier users. Datacenters are being built out for a small number of commercial users (e.g. Amazon's core business) and the size of modern HDDs would lead me to estimate that storage is about free in a modern datacenter, the scarce resource is disk-time for read/write operations. That is, projects like glacier let Amazon sell disk that would have otherwise been stranded.

It is also the case that a consumer level service like glacier presumably has more redundancy than what might be needed for best-effort storage of these recordings, where losing any fraction of them wouldn't really be a problem.

Re: Police seek Amazon Echo data in murder case

#30

Post by darkstar999 »

FrancoDiaz wrote: post #24
Flammy wrote: post #3

I'm curious if the police will push this, as it could reveal how much voice information is actually stored. Amazon has declined to answer how much voice information is stored online[1] and how much if that is tied to your identity. We do know that Alexa stores a list of queries you've spoken, and you can "delete" these records, but it is unknown if this impacts the actual voice data behind them. [1] https://www.amazo…

Wait a minute, we'd already know if Alexa was recording everything by the network traffic that obviously has already been sniffed. We can assume that Amazon is storing every "Alex,..." query that you've ever done. So what is there to know?

> We can assume

That doesn't solve a murder.

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