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Comment by brnt | Hacker News Reader

I don't recall the source rght now, but I once saw it calculated that recording every phone call in the US would cost the NSA about 20M$/yr in terms of datacenter storage. This means any government not absolutely destitute is able to afford to record all domestic phone calls.

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Doing a little dimensional analysis:

MP3 is about 1MB/minute

Assume 5 minutes per person per day on average

AWS Glacier costs 0.4 cents per GB per month

So I get a yearly cost of:

    (365 days) * 
    (5 minutes / day / person) *
    (1MB / minute) *
    (0.001 GB / MB) *
    ($0.004 / GB / month) *
    (12 months / year)
    
    ==
    
    $0.088/person/year

Which is pretty much $20M/year for the US adult population.

Good quality for a phone call is 2 * 64 kbps, but you can go down significantly (probably around 2 * 8 kbps; that's more than GSM half-rate, with modern codecs it could actually sound acceptable). [edit: added spaces to avoid multiplication being misinterpreted as formatting]

More importantly, in order to effectively exploit these phone calls, they'll want to transcribe them. Transcription AI is getting better and cheaper every year, especially when you can use custom hardware. Then, you can store the full voice recording for "interesting" calls (e.g. activists, their contacts, people with "suspicious" patterns etc. - it doesn't have to be accurate, storage is cheap) for a few years, and transcripts for everyone basically forever.

Encrypt your calls people!

> they'll want to transcribe them.

That's how in the beginning of Brazil 1985 film Archibald Buttle got arrested.

> around 2 * 8 kbps; that's more than GSM half-rate, with modern codecs it could actually sound acceptable

It’s not only acceptable, it’s widely used. I.e. lots of companies use g711 codec with 64kbps for internal intra-office communication and g729 with 8kbps voice bitrate for inter-office communication (with transcoders on the perimeters). It has been quite a standard approach to corporate voip design for years (decades). That said there is currently a shift to modern high- and adaptive-bitrate codecs, but it’s not instant.

> and g729 with 8kbps voice bitrate for inter-office communication

Why do they do that?

Even if 1000 people are making a phone call at the same time, that's just 64 Mbps each way if go for the full bandwidth, and an office this size surely must have a beefier Internet connection than that. Why skimp on something so cheap?

> MP3 is about 1MB/minute

Depends on the bitrate and number of channels.

Phone calls are mono and probably something like 48kbps (96 / 2) which would be about 360kB per minute.

With a more modern audio codec like Opus, which does better at low bitrates, a minute at phone-line quality would take around 80-120 kB, one third of MP3. Which makes it even cheaper.

This of course doesn't include the cost of intercepting at all relevant points, or the ability to ingest it in real time, or the ability to do any reads on the data (which Glacier doesn't provide real-time).

It is probably still a drop in the federal bucket.

How about web traffic?

Vast majority of web traffic is netflix and video streaming, if scoped properly to text messaging only, would be trivial amount of data per person.

The NSA is said to have 5 zettabytes at their data center in Utah[1]. It’s been rumored they could take a snapshot (I’ve heard 30 days) of the internet and process it there. Not sure if they meant the US internet or everything they consumed combined. All rumors except my one link.

[1] https://www.npr.org/sections/alltechconsidered/2013/09/23/22...

Of course a big part of what the NSA does is manage the scale. To do that they need metadata both collected with the calls (e.g. what numbers the call was from and to, if available who or what that number belonged to at the time) and assembled by analysing the audio ("male speaker", "Russian language", phrases or words maybe phonetically)

After all it's all very well having every phone call, but you can't possibly listen to them all, so you need a way to find those that you do want to listen to.

"Pervasive Monitoring is an Attack" is current policy of the IETF and accordingly new protocols are intended to combat such monitoring, but there is a lot of metadata revealed by your activities and masking it takes considerable effort, while outfits like the NSA are very enthusiastic about gathering whatever metadata they can find and discovering new ways to collect more.

$20 million in data centre costs and $2.4 billion a year in consultancy fees.

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