Given the general drumbeat of just how various groups have convinced cell phones to leak more than they ought, plus the general trend of “Oh, yeah, of course the OS sends that upstream, it’s on page 30,754 of the EULA you ought to have downloaded before you bought the phone…” revelations, at what point does one consider carrying a cell phone (of the “smart” variety) to be more harm than good?
Paper notebooks cover an awful lot while out shopping.
I know it’s not a perfect solution, and not for everyone, but I bought my last phone after checking that it was supported by LineageOS, and installing it first thing. Next phone I might try something Graphene supports, but that won’t happen until the current one breaks.
Not a perfect way to eliminate data leaks, but at least there’s no software (above firmware anyway) running on there without my say so.
I’m not much of a phone power user. Still, I find myself resenting carrying it around more and more. For now I’m leaving it in the car at least. I don’t need to know an email came in while I’m in a store, I’m not going to reply to it until I get back to a keyboard anyway. But it’s still in the car if I really need to make a call, lookup directions, etc.
AFAICT, having even a dumb phone allows for a remarkably accurate level of tracking and information gathering, because a great part of that logic is actually embedded in the cell networks themselves. The higher the frequencies used, the more accurate your positioning is - another reason the 5G networks are so concerning is likely that they’re <1m accurate, and because they’re so high frequency, there need to be a lot more antennae, including underground and in buildings, so you’ll be much more likely to be tracked easily nearly anywhere you go that has coverage. 4G is bad enough, and I’ve heard accuracy quotes of ~1m in ideal conditions there as well, although you’re not permitted to use that for yourself, or people would freak out knowing that that’s possible, so what the phone has access to is either deliberately fuzzed or qualcomm is not permitting the higher accuracy logic to be included on the device silicon at all - not that it needs to be there in the first place.
As for “should you”… that’s a mixed bag. It depends on why. I don’t run a lot of non-vendor software to begin with, on my phone, and it permits me to enable/disable location services only for software I permit (and often then only when using the software actively), so I’m comfortable with that level of tradeoff. If you live in a city, you’ll be tracked by a thousand types of sensors already, so you’re not particularly giving up any additional privacy by toting a personal tracking device with you. If you don’t, there might be better reasons to avoid one, and ham radio etc. can be a great way to remain at arm’s length from family or other folk if you have a genuine need to be reachable at a distance from time to time, 'long as you don’t mind others knowing your business.
However, as anybody will tell you, it’s a situation of risk assessment. I’ll be blunt - anybody with a fixed address is trivially findable, period. They don’t need to track you. They know where you (and your wife/husband/daughter/son/pet gerbil) sleep, which stores you likely shop at, and the limits you’ll be able to practically go to to find needful things in a go-to-ground situation. If they care about you at all, they know already all of your points of contact, your friends and their friends, and probably have a largely accurate psychological profile of you built up from things as simple as your credit card/bank card purchase history, your online ordering and mail delivery contents (why the US is giving up that aspect of internal spy capacity I have no idea), hell even if you only ever spend cash, you think the stores you go into don’t have networked security cameras (or that the cheap shitty non-networked ones they have aren’t compromised in some way)? Face it, you’re being tracked, in aggregate, in the deep infosphere all the time, and afaict there’s no way around it unless you’ve been diligently outfoxing them since before you were born, or they legitimately think you’re dead and you’ve not appeared on anybody’s facial recognition at all since.
This is a sane approach, though I frequently find myself wanting to look something up in the store (or at least comparison shop things). I’d argue that the right solution to emails is actually just turning off notifications or push services, period, though. Email is not a time sensitive communications system.
I disagree slightly with Vertiginous’s observations on how tracked we are, but I also live in a rural area, so we don’t have things like networked security cameras everywhere. I’ve not been to a modern city recently to figure out how bad things have gotten.
Yeah, I did point out that if you don’t live in a city you’re likely to get bigger benefits from avoiding a cell, in acknowledgement of that very point.
One other thing I’ve been experimenting with is actually turning my phone off in the evenings. I now get 4+ days of battery life on a 6S. I suppose I should probably have a house phone for people to call in case of emergency, but there’s relatively little that would require immediate contact with me at night.
I’ll probably rotate this one to a house phone when I replace it at some point - put it on one of those super cheap “Pay if you use it that day” plans or something.
For me? Yes. If I need to go dark, I’ll go dark. In the meantime, well, I wander around zero cell areas enough that ‘going dark’ isn’t a big thing in my patterns. And even then, I carry an inreach in case … well, you know.
The downside of always carrying a phone except when you’re up to something is that it becomes “unusual” for you to not have a phone - whereas if you regularly leave it behind, that’s just something you do.
I don’t have any great answers either. Though a ZeroPhone or PinePhone might be fun to play with, from the general perspective of “It working is a rare case, but it still counts as a phone.” 
One interesting new feature in iOS 14 is the ability to offer location-based applications a general, not specific location.
Settings → Privacy → Location Services, and then for each application, there’s now a “Precise Location” toggle. The concept is that if you are playing Ingress, it needs to know where you are, but a weather app just needs to know that I’m within a few miles of my location.
Continuing the debate, Upturn recently released an {article, short book} talking about the extraction of data from cell devices, in the context of police arrests/investigations/etc.
Despite what they like to claim, it seems that for the most part, law enforcement has no trouble at all getting into most of the phones they’d like to get access to - and do so quite regularly, for the purposes of rooting around and figuring out whatever they can.
It might be worth writing letters to your local politicians mentioning this, and asking them to investigate if the capabilities are being used responsibly.
Small aircraft went down a couple months ago. Eastern Oregon IIRC. It had the old 121.5 ELT, and the article said the Civil Air Patrol used a combination of the last transponder data and the pilot’s cellphone position data to find the crash sight.
I was surprised. Even the C-A-P has access to cellular position data whenever they want? This wasn’t a post-crash investigation into what happened, days later, after subpoenas or whatever. This was how they found the aircraft after it went down.
“Our app uses AnOnYmOuS LoCaTiOn DaTa to improve your experience…” Well good for you guys. Looks like the tower operators get up to the minute position data whenever they want…
I’m sure CAP is working with 9/11 and as a SAR agency, though. And not rando volunteers tapping a database, if it helps.
Besides, it’s totally fine if your location is sold to foreign military analysis, right? If the US is doing it, I guarantee other countries are doing the same thing.
I’ve found that increasingly, it makes sense to have my phone off when I’m out if it’s not a work day. They can leave a message. I’ll check it when I get back.
I figure the ‘on demand’ method of my device connecting and transmitting / receiving information is probably, honestly, the best way to go going forward for now. Hopefully it mucks up the tracking and info gathering methods at use somewhat.
I’m aware there may or may not be true ‘off’ states for these things, but on the other hand, I’m sure it disables some of the data gathering if not close to all.
I would generally trust a modern phone to be “off enough to not talk to cell towers” when “off,” if not backdoored/malware compromised. And it’s the sort of thing that’s easy to test - leave it off for a day, check battery charge. You can’t both be off enough to not impact battery, and remain powered on.
Turning them off is a pretty nice option, though, isn’t it? Or just leaving it at home.
We actually have a reasonably believable test case for Motorola’s recent Moto G phones; We left some of them off (after having been used daily) for about a month. Both phones having been charged before being shut off, were at 99% remaining when turned back on.
This also did not appear to be a sensor / BMS type error, as the phones were put back into service when we turned them back on, and the battery life did not seem to be less than usual at all.
So, in terms of, ‘is the thing still doing something’? the answer does appear to be an emphatic, “No, it’s off.”
It certainly can’t have been doing very much over that month with only ~1% of that battery used over that time period.