Is this behavior expected? I would imagine it would be a privacy violation in a multi-user system. I thought they had some sort of encryption for hiding the sites that I visit.
BTW, FF does not do this on private mode. But still it is concerning, that any program can know about the sites I visit just by looking at ~/.mozilla/profile/storage/default.
As other noted, that’s the case in Linux, by default all processes are equal, so if your shell process can access a file, the Firefox process can access that file.
But there are in fact many ways to sandbox processes and prevent exactly what you are worried about. One way is to install applications via Flatpak (or Snap), that can limit what files the app can see, while still running as your user.
If there is an app you need and don’t trust that’s not available as a flatpak (or snap), there are ways to sanbox it manually. It does require some tinkering, but people can help you on !linux@lemmy.ml