About smartphones, I forgot to add something:
Firmwares and bootloaders aside, the real threat is the modem integration
inside the machine. Unproven bad modem isolation, I'm not sure what this
means, but it's not really convincing.
Which leads me to to use it (turn it on) as little as I'd have to (that
includes no e-mails, even encrypted, and no real personal data because of the
tight modem integration).
When I think about it, since it's unsafe to use personal data on a
smartphone, the only useful features compared to a dumbphone are the apps.
Like reminders, quite useful.
So I'd say to my older self to:
The smartphone is in essence an emergency phone.
Phone calls, text messages, maybe an app or two, period.
Keep the battery off as often as possible.
ideally get a Replicant phone anyway, but if it's not possible, any
smartphone will do, according to the use I make of it.
If possible, get some very small and disconnected device that can run
Android/Cyanogenmod/Replicant for F-droid apps.
