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.
I've chosen to err on the side of estimating it to be more expensive, because I think that makes the end result more convincing:
30m is chump change for parties like Amazon, and in reality it'll cost significantly less. 1m might well do. Maybe it's less still. You could combine flagging users with flagging low-certainty or keyword-containing transcriptions.
Either way, you don't need collusion with intelligence parties, just an unscrupulous or naive exac at Amazon that thinks the data might be worth a lot for training future learning models. Of course the more sinister but legal reselling to government agencies is a financially attractive option as well.
1200 bits per second is almost enough for toll-quality speech -- and I'm referring to the state of the art a few years ago. Speech codecs are probably better now. But let's stick with 1200 bps. That's enough to store continuous speech in the vicinity of the device for a year, using only about 5 GB.
My guess is that if you cared only about intelligibility and not fidelity, you could do the job with 10%-20% of that space.
So yes: Alexa could easily be collecting and storing a vast amount of data that isn't immediately transmitted or used.
"Get BGP+IPv6+IPv4 for $0.25/Mbps!"
I thought it was HE, but it must have been someone else that had a 10Gig deal for $2,000. Either way, that's for a single 10Gig link. If you're buying 100Gb - 1Tbps like Amazon is, you're probably getting an even better deal.
We just signed a contract with Level 3 for slightly more than the price you mentioned, but they had to build into us; which costs them ~$120k out of pocket, thus the higher price.
What about abduction cases, inside trading, tax fraud, drug and human smuggling? There it could help to have data from months ago, so any newly discovered targets instantly come with a bunch of evidence.
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.