Don't allow files to be read by everyone

[Philip-Scott]

Looks like by default, created files on home can be read by anyone on your local machine by just traveling to another home directory. I think the default is currently 644 which gives read permissions to everyone.

[tintou]

This is a valid concern, take in mind when fixing it that the greeter need to access to user-specific content like user-image and wallpaper.

[arshubham]

I can also access files from other OS installations from elementary without a prompt for password. I have a dual boot with fedora rawhide. On accessing elementary partition, nautilus asks for root password but elementary file doesn't when accessing fedora partition from elementary.

Does this case relate to the issue or is this a separate issue?