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!
That's how in the beginning of Brazil 1985 film Archibald Buttle got arrested.
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.
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?
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.
It is probably still a drop in the federal bucket.
[1] https://www.npr.org/sections/alltechconsidered/2013/09/23/22...
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:
Which is pretty much $20M/year for the US adult population.