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Comment by kornhole | Hacker News Reader

This is what I have done for years: Cellular is always off anywhere near my house. I only turn on cellular when needed. I use Graphene which allows WIFI to be used without cellular for my VOIP calls on voip.ms or jmp.chat. I have been using prepaid cash purchased SIMs but might switch to silent.link. The only way for the carrier to know where I am is if they do something funny on the proprietary baseband modem.

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I gotta ask... why? It's your house, anyone who could get your info from a teleco and wants to know your location almost certainly knows your home address, so this is just to protect from know when you're at your house? If you're still turning on cellular around town too, a decently useful map of your location history would exist anyway?

I'm not trying to be snarky or anything, I'm genuinely curious here what the benefit is to you.

I don't have a link handy but the last time I interacted with the user you're replying to, it was also about cell phones, and they were doing dumb things like swapping SIMs with their wife, thinking it would make things more private....somehow.

Guess what a SIM card does when it's put into a new phone? Includes the last IMSI it was installed into when it joins the carrier's network.

They're not very well educated on digital privacy and engaging in a lot of cargo-cult privacy stuff that is almost certainly making them stand out like a giant red thumb. Very few people do things like switch SIM cards on a regular basis, at least ones who aren't engaged in criminal enterprises.

Their behavior reminds me of a former partner's ex, who was [paranoid-delusional | obsessed with] cell phone tracking.

I really have no idea why they're so concerned about their cell phone carrier "knowing" their home address.

I simply don't like people following me around wherever I go and keeping a record of it. I am pretty boring in that way and most others. Rotating SIM cards and devices does not create privacy, but it does create confusion on network maps if someone tried to identify the owner of a SIM or device by analyzing travel patterns.

It would certainly make you stand out on that network map compared to others who are even more boring than you are (read: just about everyone, sans criminal enterprises as noted above).

It would be hilarious and sad if some spooks focused on me or my wife and wasted hours on traffic analysis just to figure out we are average law abiding people of zero interest.

I've got a (not very) funny story I'll share on HN once I've done the write-up

The point is to keep my SIM and phone anonymous. As explained in the article, if they can see where your phone sleeps at night, they can figure out who is associated to the SIM card and the IMSI sent.

You and your SIM card is associated by law in most European countries. You can get a prepaid SIM card, but you still have to hand your data over. I have a prepaid SIM card and I have a contract for it. I also have one without a contract, but I do have to verify the data once a year. It renders all instant messaging applications that use a phone number insecure, by default.

silent.link appears available in most of EU. I do not know which VOIP providers are available to your country, but VOIP.MS expanded to EU recently. It is cheap and friendly for consumer users if you can deal with a little technical setup. It requires KYC, but if that is a problem, check kycnot.me.

> anyone who could get your info from a teleco and wants to know your location almost certainly knows your home address

I think OP might be in a jurisdiction where you don't need to provide your address (yet) when

> using prepaid cash purchased SIMs

Even then, your house would be the location you spend most of your time. You'd have to be really vigilant to switch off your cell functions when you go near your house most of the time, and not always at the same place (otherwise a clean gap in the map will reveal where you live).

If you want to be untraceable you don't use cellphones, simple as that. Of course modern life is ridiculously difficult that way so it's pretty impossible.

Right, but surely he had to prove identity when buying/renting the house? Maybe the telco doesn't know - but if someone could've gone through them to get his home address, they could also have gotten it through other means?

There are plenty of cash rental options out there.

On that note, it is legal to give crossroads as home address in the USA.

Really? Where do they deliver all the ads to in that case?

But, your WiFi may still leak your location, eg:

https://arxiv.org/pdf/1807.05716.pdf

Right. I forgot to mention that when I leave my home, I turn off WIFI and bluetooth. I turn it on only when at home or on a friends home network.

Doesn't your phone ping off the tower regularely anyway? I've always understood that without a physical switch to the antenna there's no way to actually know

Yes that was my caveat about the proprietary baseband modem that we cannot totally control. If I was in a different threat model category, I would use a phone with physical switch to the baseband. Those devices like Pinephone and Librem that only run Linux are not quite mature enough to fit my needs. They may be my next choice.

Very cool!

I looked into it a little bit, a good option depending on your threat model is to simply leave it in a faraday container (read: aluminum foil envelope - or the more sophisticated stuff) when you don't want it to be visible. But then, you kind of have to let go of having that phone usable at home at all, and end up having a "dirty" and a "clean" phone. Then again, just useful depending on your threat model.

> This is what I have done for years: Cellular is always off anywhere near my house.

Do you disable cell service manually when you're going home?

Yes. I only turn on cellular away from home and when needed. I don't need to be always connected.

If it pings the towers anyways, what's the point of turning it off?

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