Hacker News Reader

> Power it off

This has been the real game changer for me. As instant gratification is not so instant, I can go way larger stretches of time without checking the phone. Also, as nowadays most people message, and calls are not so common (at least in my circles), there is no "harm".

No notifications of any kind + airplane mode unless I actively need to use it is my way to go for the last few years.

gmaps is the last useful thing that tech came up with so I'm not going to entirely give up smartphones, the rest can die I don't care much

That's quite reasonable. You might consider the Open Street Maps clients - OrganicMaps is one I've played with on tablet. That gets you navigational data, but works purely offline and isn't trying to stream your data out.

OsmAnd is what I'm using now, since the quality of Google Maps navigation for me has fallen off a cliff.

I miss having a quick toggle to turn GPS on and off. It was on some of my early smartphones. Now I have to dig into the location menu...

> Yes, in an ideal world, none of this would be a problem. But that's not the world we have right now, and I don't believe that minor modifications of this concept of device can improve the state of it. I've been trying for years to figure out how to make digital consumer tech less-toxic, and the only conclusions I've come to are, "You can't."

I don't see what's so hard about it. Root your (Android) phone; throw any app you want to use into Ghidra and strip out all but the desired functionality. Presuming you only need a few key apps, it would take maybe a few days every few months to keep it going against updates (or less if you can come up with dynamic-library-shim approaches to modding, instead of using binary patching.)

In other words: rather than waiting for an open-source mobile ecosystem that'll never come, we should just be treating mobile devices like we do game consoles: seeing them as something to be jailbroken, modchipped, hacked, brute-forced, overridden, key-extracted, etc. Made to do what you want, and only what you want, when you want — source-availability be damned.

It's not a solution for everybody, but it can be a solution for those who know how to do it. (And if there were a thriving ecosystem of people doing this work, then the work itself could be repackaged for cargo-cult consumption by those who don't really understand it, but are willing to follow a "modding guide" or pay to have it done by some guy on eBay.)

---

I should note separately that if you're concerned about being tracked, a flip-phone is still a terrible thing to carry around (if you're carrying it with the battery + SIM card both in it, which I assume you are.) Cellular carriers are 10x as nosy (and state-actor-infested) as the average app company. Cellular baseband chips will still be passively pinging nearby radio towers with the phone's IMEI and the SIM card's ICCID, even while the phone is "off" — as long as its battery isn't dead/removed.

Smartphones can't prevent their baseband chipsets from pinging towers any more than flip-phones can, of course — but at least if you're using a smartphone with only an eSIM, then (on a jailbroken device) you can at least install a background service that will have the application processor tell the eSIM chip to present itself as unpopulated whenever the phone is locked; and perhaps send a command to scramble the baseband's configured IMEI right before telling it to go to airplane mode, too. (I presume here that you would be willing to trade off being unreachable by calls except when "ready", for not having your location tracked by the carrier except when your phone is awake + unlocked + being interacted with. You'd still be reachable by text — SMSes get buffered in the receiving SMSC until the subscriber comes back online!)

I think you have the right mindset about the most ideal approach, but how-to guides on how to do this *such that* it is only *a few days every few months* to maintain a setup like that are few and far between... as in there aren't any.

Sure - same page, digital sovereignty isn't free, if you want it have to work for it.

But, speaking as a technical securtiy user myself, and have worked with ghidra, I have zero context on how to take the approach you call for that cleanly strips out the bad stuff without buying me, what would feel to be likely, hours upon hours of troubleshooting dependencies for core functionality that I inadvertantly broke due to the surgery... such that I'm back to not carrying a smart device or being ok with a fliphone traingulating me.

One approach I have thought through with effective (I think? still considering this) privacy outcomes is leveraging LLCs and related device plans as a "cloaking" mechanism. If my current phone stays at my house always, I travel locally with a fliphone, and travel with a network of smart phones under LLCs, that could be enough to throw off the tracking effectively while only (maybe?) exposing data that's already exposed in public records.

I don't get nearly enough benefit from a smartphone to bother with any of that sort of deep aggressive reverse engineering and patching. It's not worth the time. I don't have a spare "few days every few months" that I want to dedicate to reverse engineering apps that are purpose built to work against my will.

> In other words: rather than waiting for an open-source mobile ecosystem that'll never come, we should just be treating mobile devices like we do game consoles: seeing them as something to be jailbroken, modchipped, hacked, brute-forced, overridden, key-extracted, etc. Made to do what you want, and only what you want, when you want — source-availability be damned.

Except there are far easier to use options that aren't nearly so locked down, should I want to do general purpose computing. I think the most recent game console I owned was a Wii, but I treated it largely as a fixed purpose device that did a few things well.

I generally move around with my flip phone in airplane mode, then shut down (airplane mode saves state across power cycles, so I can power it on if I want to take a picture of a flyer for some event without having it ping out). But I'll ask for a citation on "Pinging towers while powered off." I'm aware of some attacks on devices that fake a poweroff, but based on "battery state of charge when powered down" analysis (which admittedly isn't very deep), I've seen no evidence of any sort of substantial power draw when shut down - and some of the places I go, there aren't any towers nearby, so it would have to try fairly hard to reach one.

But I'm really not sure of how much of your high effort spitball here is actually things doable, or if you assume I've got the time to fully reverse engineer a modern device to, say, scramble the IMEI in the baseband (it seems like the sort of thing there wouldn't be a command to do, so that implies remote code exploits in the baseband to be able to add that capability).

It's way, way easier to just not carry a phone.

> But I'll ask for a citation on "Pinging towers while powered off."

Here's circumstantial evidence pointing to the negative: that a device in airplane mode, and probably, by extension, a powered-off device, broadcast no signals:

Most people carry their mobile device with them everywhere they go and leave it connected to the mobile network at all times. While they are sitting at home and playing on their device, they are connected to their cellular carrier for convenience. They might switch to Wi-Fi while streaming videos at home, but most people still leave the cellular modem activated, which is constantly recording the location of the device. I believe this is risky behavior and a desire for extreme privacy will require you to take more extreme action.

Some of my clients' primary mobile devices have never entered their homes and have never connected to a cellular tower within five miles of their houses. This prevents their phones from announcing their home locations. If someone did figure out a mobile number, and paid a bounty hunter or private investigator to locate a device, it would not lead anyone back to a home. The last known location should be a busy intersection with no connection to anyone. In the past, some clients have used a secondary mobile device with no cellular service within the home, which only connects via Wi-Fi, but I find this complication to no longer be warranted. For most GrapheneOS users who have the discipline to control their cellular, Bluetooth, and Wi-Fi connections, I believe you can safely use your primary mobile device in the home as needed. Please allow me to explain.

I insist on preventing any devices from connecting to any cellular network while in or near my home. These connections can immediately identify someone's location. When you place the GrapheneOS device into airplane mode, the cellular connection sends _absolutely no data to any cell towers_. The ability to block the microphone and cameras from the Quick menu further calms my worries. Unlike Apple devices, airplane mode is not disabled during updates or reboots. I simply trust GrapheneOS to maintain my desired connections more than Apple.

(from Michael Bazzell's Extreme Privacy: What It Takes to Disappear, 5th edition. Emphasis mine.)

The counter-evidence I'll cite comes from language used by criminal investigators in true-crime television like Forensic Files. I recall several instances of language like "we realized that the suspect then disappeared off the grid — meaning that either the battery in their cellphone ran dry, or more likely, was removed." They never consider the possibility that the suspect powered off their phone — suggesting (to me, at least) that that's not a concern for them.

Thinking more closely about the implication of this, I think the feature I was positing probably exists, but isn't an always-active signalling feature in the way I described in my GP post. It's not that the baseband will (for a regular, non-wiretapped person) periodically reach out to ping towers while the phone is nominally off — which would indeed continue to drain the battery perceptibly.

Instead, my thinking is that one of the following two things are true:

1. Phones need to be powered on to receive an "activate persistent baseband wiretap" message; but once they do receive such a message while powered on, powering down the phone will no longer fully power down the baseband, and the baseband will instead continue to silently register itself with nearby towers.

2. Whether or not the phone is powered on, as long as the baseband receives power from the battery, the baseband will wake up every so often just enough to receive periodic announce broadcasts from nearby cell towers. And part of these periodic broadcasts, is a set of queued "system" SMS messages — broadcast to all subscribers rather than directionally-MIMOed to just the intended subscriber, but each encrypted for a specific device. (This would be, in effect, the cell tower acting a bit like a Numbers Station.) One such "system" SMS message can activate silent-persistent-baseband-wiretap mode. Once the baseband receives such a message, it will stay awake from then on, and begin actively pinging cell towers. (At which point the "system" SMS message will be considered ACKed and removed from the service provider's SMSC's system-messages queue topic.)

In either of these cases, only people actively being wiretapped would begin to experience perceptible battery drain.

In the first case, there'd be no additional battery expense for regular, non-wiretapped subscribers — the baseband would be receiving the wiretap message like it receives any other SMS, and only when it would receive other SMSes. Given that SMSCs queue SMSes, you could have a phone off for a while to prevent wiretap activation; it would only get wiretapped the moment you turn the phone back on. (But once wiretapped, turning it off would no longer help.) If criminal organizations knew this, you'd expect to see a specific pattern of use for "burner" devices from them.

In the second case, there'd naively be a barely-perceptible additional battery expense. (But maybe not — in theory, the radio could have an independent little circuit for this that is powered by the cell tower in a process similar to RFID! After all, it only needs enough smarts to recognize one particular message and tell the rest of the baseband processor to wake up. Like the "wake word" DSP on a smart speaker.)