Linux Phones

what’s your alternative?

I don't bring a phone with me, usually. "Open phone" is an oxymoron, modem firmware is a black box. "Secure telephony" is an oxymoron, it's unencrypted and SS7 access is being sold which lets people even impersonate phones on the network.

You could use some VoIP provider (jmp.chat?) or get a landline installed for times when you ABSOLUTELY NEED a phone number, like for a hospital that mandates it for a reason or another. Or ask relatives if they have some keypad phone lying around (unless your country no longer has the infra for them, ahem, the US, ahem). In some locations, you can buy a phone with a prepaid plan that you can just not bring home afterwards (return / give away). For work, ask for a work phone/SIM or just get a pair that you only turn on at work. I have said something about MediaTek keypad phones recently, can't be bothered to click out to copy paste it here so just check my reply history I guess... I will quote some more intelligent people here (CC-BY-NC-4.0, "anarsec"):

To prevent your movements from being tracked, treat the smartphone like a landline and leave it at home when you are out of the house. Even if you use an anonymously purchased SIM card, if it is linked to your identity in the future, the service provider can be retroactively queried for geolocation data. If you use the phone as we recommend (as a Wi-Fi only device that is kept in airplane mode at all times), it won't connect to cell towers. It's not sufficient to only leave the phone at home when you're going to a meeting, demo or action because that will be an outlier from your normal pattern of behaviour and serve as an indication that criminal activity is taking place in that time window.

That advice is clearly for people protesting, but even if not, some govt official could think you were at some illegal event.

Personally, when I do bring a phone, it's usually to feed the addiction :/ . I have a phone from like 2016 with LineageOS which I basically only use for 2FA when mandated (not often at all) and to scroll Lemmy from public Wi-Fi. Native(-ish) apps run really fast to me (my Lemmy client is Jerboa), but a modern browser is extremely slow and often crashes background stuff (and itself) due to RAM. Thanks, the W3C. And also Google for making an OS so bloated. I have a copy of Chawan in Termux for a special occasion. Apart from that, I may also (very rarely) bring a PostMarketOS phone (SXMO-de-sway/SWMO) just to write code or something else (although touch keyboards suck and I often find myself waiting until I am home and have a proper keyboard). Too bad the Nokia N900 is so rare and expensive... Anyways, if I really wanted to, I could buy a SIM card from a grocery store, shove it up one of the phones, then do my thing and throw it away before getting airplane mode again and arriving home. If I were to do that multiple times, it would absolutely blow privacy due to radio fingerprint and IMEI, though.

Annoyingly, my specific device port of LineageOS doesn't have Wi-Fi MAC randomization support enabled at build time for whatever reason, and building Android is a complete pain requiring insane amounts of RAM and storage, managed to just barely advance in the build scripts to get it to compile a boot image with the kernel (itself needs much less resources lmao, it's the fucking build script). Sooooooo there's that. And even if I fixed it for everyone with a patch, LineageOS maintainers will just let it sit on the platform (that is ironically Google account only) forever and ever with a -1 score. BUT normally Android is set up to wake up the phone every .03 picoseconds and put itself back to sleep which is how it connects to Wi-Fi, and since I don't have Google services AND it's in airplane mode constantly, it has no events to wake up for and literally doesn't connect to Wi-Fi until I press a side button. That with the hostname being set to a single space character, good enough.