Phone number privacy (limiting profiling)

Questions
1

Hello to all

To try and limit data collection when giving out a phone number, I do the following:

  • Utilise around 4 devices, each with their own physical SIM
  • Devices are not latest models but purely used as dumb phones
  • Devices do not leave home
  • They are not connected to wifi, bluetooth etc. Location is off, no other apps installed, majority running a clean LineageOS
  • SIMs are cheap as I generally only use to receive calls or texts. PAYG top up only needed maybe every 3 years but I will generally burn most numbers every six months

Although no silver bullet, Iā€™m just trying to muddy the waters and limit profile points. It also allows me to shut off any comms temporarily, or permanently.

Assumed leakage:

  • The carrier has (a) name and address so can at least correlate these numbers if they wish
  • They can obtain location via cell tower connections
  • They can obviously log all calls and texts
  • The IMEI and SIM number are logged

Questions:

  1. Is there any other data leaked to carrier while the SIM is active?

  2. Is it completely redundant using separate devices? Is there no further cross contamination etc? Single device would likely run GOS

  3. If switching to eSIM, is an app always required (giffgaff) to install? this also then requires playstore/aurora :frowning:

  4. Assume a VPN on device is not required as no (relevant) data is being transmitted?

  5. Is the carrier likely to be correlating all accounts and selling as single profile to data broker?

2

Your IMSI number too. IMEI number may not be ā€œleakedā€ to the cellular provider.

I suggest sticking with a single device. What youā€™re doing to me sounds insane. Sorry. And yes, GOS is ideal.

Always use a physical SIM if possible.

Donā€™t know what you mean here. Always use a VPN for enhanced privacy you get with obfuscating your internet activity from your ISP.

Most likely, yes. Depends where you live too.

2 Likes
3

Why?

Some carriers do app-based provisioning. Itā€™s totally unnecessary, but it appears to be quite mainstream. Using the QR code provided by the carrier is much cleaner option. These apps will typically depend on Play services. giffgaff is one of them.

I agree with @SmartCondor. What youā€™re doing is unsustainable and unnecessary.

1 Like
4

If you at all at any point donā€™t want the cellular company to triangulate you, you can always take out your SIM card physically. Not possible with eSIM unless you remove your eSIM in full but then you have the hassle of getting it installed back.

5

Not having a SIM or eSIM doesnā€™t turn off the radio. Whatā€™s the difference? Just use Airplane mode with both.

6

It depends on how one wants to go about it.

7

Thank you both for the replies.

Regarding the use of a VPN, as stated, these devices are not used for anything but calls and messages. The carrier already logs these ā€“ what other data would a VPN obfuscate?

Regarding the eSIM vs SIM, the carrier already knows my address (and I donā€™t take these devices anywhere), so this is a moot point, I assume.

I am resigned to giving up the above info to the carrier (as the other options are too costly) but I am still trying to avoid being tracked and profiled by other companies that sell my number to data brokers.

Itā€™s not a huge effort as these are generally phones that I have previously used as main driver; Iā€™ve just repurposed them, but yes, it would be good to stick to a single device, hence the question.

Are you advising that I just stick to a single number, or something else?

In case it was unclear, I do have a device with a personal number that I give to friends and family. Iā€™m not that hardcore.. but Iā€™m wondering whether I should wait a few days before asking my next question about browser separation and trying to cut down on devices and VMs :face_with_peeking_eye:

8

Consider having them via Signal. For that you can use a VPN especially if Signal is blocked in your country.

You want privacy but youā€™re going to be using regular calls and SMS? That doesnā€™t add up and make sense to me. But just know that Signal would be a lot better.

9

I appreciate the advice but I think weā€™re at crossed wires somewhat..

My daily driver is a GOS device. I use Signal to communicate with friends and family where possible.

The devices above are used purely to give out to companies that require a number, i.e. restaurants, quotes etc. Where possible, I try not to give out my real name and address, for email I can use an alias. I am also trying to limit exposure to my ā€˜realā€™ number.

These companies would not use Signal, and only accept calls and SMS.

1 Like
10

Iā€™m not convinced this is going to work. In the US, all postpaid plans require an ID and a credit check. They know who you are so how will your idea work? In China, even prepaid requires KYC.

11

You canā€™t call a restaurant with Signal. I still have to make a regular phone call when dealing with the rest of society.

2 Likes
12

This is working and has worked for the last 2-3 years. As per OP, this is not about shielding my ID from the carrier, but about not giving out a number that can be tracked across data brokers.

There are so many websites, stores and other institutions that now blindly ask for your number, and often you canā€™t continue until a valid number is entered (then sms validated).

This is my solution, however, I was looking to streamline as per opening questions.

Edit: This is not a complete solution, just a piece of the puzzle

13

My guy, why donā€™t you just give out VOIP numbers? Use a service like JMP or MySudo and you can have plenty of numbers to give out for dirt cheap and turn them on or off at will while only needing WiFi access.

1 Like
14

Yes, I hear you. VOIP numbers are the holy grail for me, however, they are around Ā£5 per month. Thatā€™s Ā£180-300 per year (3-5 numbers) just to stop the evil data brokers sucking up my phone number.

I want to spend my hard earned money on things I enjoy, so at that point Iā€™ll either tap out, or give up and provide a number. I do get some satisfaction if I can successfully click through a web form after entering 012345 111111 for the number (when the number isnā€™t needed) :smiley: .