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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

#11

Post by sdegutis »

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...

In fact that's just 40gb per year, which is pretty doable even on a local SD card that Alexa could be fitted with. Or even if it stores one month and deletes the oldest one every day, that's still 3gb. Very doable.

Re: Police seek Amazon Echo data in murder case

#12

Post by MichaelGG »

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?

A year of audio at 32kbps (more than enough for speech) is only 120GB. That's only a couple bucks of month on S3 -- at retail pricing. So it's technically and financially feasible to store everything if Amazon wanted to.

Re: Police seek Amazon Echo data in murder case

#13

Post by cryptarch »

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 Alexa's are active at any given point in time that works out to 380k PB. Ok, that doesn't work yet.

However, if you then layer on a flagging system, where only certain users' full record is stored, or only "suspicious incidents" are stored, and you get this down to only flagging 0.1% of all data, you arrive at 380PB of storage.

Amazon Glacier costs about $88.000 a year per PB, but there's a profit margin included in that, so I'll assume it costs Amazon just $75k a year.

In conclusion, it would cost Amazon about $28.5m a year to run such a system. That's certainly within the realm of possibility and of what LE/SIGINT clients would pay; I assume the NSA would gladly pay that sum x100 for that capability. Sounds like it'd be booming business for Amazon.

Re: Police seek Amazon Echo data in murder case

#14

Post by Nadya »

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.

Especially since Alexa already converts it to text! It wouldn't be outside the realms of possibility.

Would it be possible to test this? Check the battery life of the Dot in a completely silent room vs the battery life of a Dot listening to an audiobook played on repeat. If it is actually listening and transcribing it should have a higher power consumption and thus die faster - right?

Re: Police seek Amazon Echo data in murder case

#15

Post by troncheadle »

Flammy wrote: post #4
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 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

Re: Police seek Amazon Echo data in murder case

#16

Post by [deleted] »

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…

[deleted]

Re: Police seek Amazon Echo data in murder case

#17

Post by FrancoDiaz »

CodeWriter23 wrote: post #7

From the privacy perspective, IMO, once you put a device in your home that you know is always listening, and is forwarding an unknown amount of audio from your home to a third party, at that point, you have surrendered your right to privacy. Edit: not just my opinion, it's a matter of law. (thanks @mnm1) https://en.wikipedia.org/wiki/Third-party_doctrine

Yep, I'm amazed at myself on how much privacy I've given up for convenience from 10 years ago. As long as you know the trade-offs...

I've started smart-devicing my home and a little wary about that, not from a privacy perspective, but from a hacking perspective. I can almost imagine a sci-fi/horror movie there somewhere.

Re: Police seek Amazon Echo data in murder case

#18

Post by api »

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?

How many other words and sounds sound a bit like Alexa?

Re: Police seek Amazon Echo data in murder case

#19

Post by _Codemonkeyism »

Flammy wrote: post #4
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 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…

Can't vote you up enough.

Re: Police seek Amazon Echo data in murder case

#20

Post by tastythrowaway2 »

alexwebb2 wrote: post #8
CodeWriter23 wrote: post #7

From the privacy perspective, IMO, once you put a device in your home that you know is always listening, and is forwarding an unknown amount of audio from your home to a third party, at that point, you have surrendered your right to privacy. Edit: not just my opinion, it's a matter of law. (thanks @mnm1) https://en.wikipedia.org/wiki/Third-party_doctrine

No, you haven't, any more than when you buy a cell phone with a camera and microphone built in. People still have rights regardless of the products they buy.

People have the rights they have agreed to. What does the EULA state? Privacy policy?
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