[bsstoner]

Hi -- Head of Product at Cape. This is a good question. I will say up front there is no silver bullet for privacy on cellular networks given the way they were designed to interoperate. Our strategy is to offer many different protections that collectively make it harder for your activity to be tracked.

The details of what our carrier partners can see is in the table at the bottom of our privacy summary: https://www.cape.co/privacy-summary. We add noise to their data by doing things like rotating your IMSI daily and spreading traffic among multiple carrier partners. If the data is messy enough and not associated with your personal information, there should be less monetary incentive for the carrier to try to piece it together when they have an abundance of clean data with stable identifiers and verified personal information.

Additionally, with disappearing call logs, it's about reducing surface area. Fewer logs in less places.

[montyanne]

> We add noise to their data

It’s interesting that Apple is going down a similar path with hardware filtering location retrieval commands and neighborhood-level blurring on their C1 modems. Really awesome work from that team by making sure they’ve considered privacy as a first party feature for that chip.

How do you guys view the relative value of privacy/security at the network provider layer of the cell stack for the average user/citzen?

Even if Cape doesn’t retain metadata yourselves (eg LTE positioning info), is that data not still retained and repackaged by the tower owners themselves? Eg babel street, venntel, etc. A rotating IMEI every 24 hours might make it marginally more difficult for logical tracking, but there’s still only physically one location the phone can be in without fuzzing at the hardware level.

I should also say - I’ve been following y’all’s work for a while (and considered some of those early forward deployed engineer positions), but I’m struggling to see how this all works as a consumer product. Would be awesome to see an eventual partnership with Apple/Qualcomm to bring this to the hardware level since privacy is a tough nut to crack even at full MVNO.

[bsstoner]

Appreciate the shoutout. We love what Apple is doing in this area. There is a lot of room for them to help improve things at the modem/hardware/OS layer.

On the tower question, you’re right, we can’t control what data is collected by the tower owners. Like I said above our strategy is to add noise through a variety of methods that makes it harder (not impossible) for anyone collecting data to track you. We also give you multiple phone numbers. I think this stuff adds up and is a meaningful improvement over the status quo for most average user/citizens.

I like to use the organic food analogy. If given the choice, why not choose the carrier that is actually making an effort not to track you vs everyone else who clearly doesn’t care?

[tangelogica]

> It’s interesting that Apple is going down a similar path with hardware filtering location retrieval commands and neighborhood-level blurring on their C1 modems.

Are there any technical writeups on this yet? I agree, it’s really cool and would love to read about how they’re doing it

[jrexilius]

A sort of related question, is the user able to actually power-off the baseband carrier chip and still keep the phone powered on? I seem to recall there being some 911 regulations around that topic. But it might be a way to enable the user to at least disable that tracking vector, while still using the phone offline or via wifi?

[simon666]

Additionally to what others have said LineageOS (Android open source OS) allows you to selectively turn on/off carrier modem and radio in quick settings just like you do for wifi, bluetooth, gps etc. You can use airplane mode which will by default turn off the carrier radio and wifi, of your can manually do this selectively.

[inigyou]

This feature is called Flight Mode or Airplane Mode on most phones. You'll know if your phone implemented it this way because your battery life will go wayyyy up while in the mode.

[ThePowerOfFuet]

That's what Airplane Mode is for.

[ThePowerOfFuet]

>Subscriber SIM number (IMSI)

You mean the ICCID?