What is the most difficult problem that you have fixed in linux?
Making a Palm Pilot getting a live connection to the internet through an infrared connection (Red Hat Linux). That was circa 2004, and I spent 10 hours, all night on it.
Privacy-Focused Smartphone Fairphone 4 Enters the U.S. Market
I have eOS installed on my old Moto G7 Plus. It's possibly the most private android distro out there, more so than LineageOS for example. Even if someone doesn't have an old device to install it on, they can buy such a phone for $50, second hand.
