Having a look at the default users & groups management on some usual Linux distributions (respectively ArchLinux and Debian), I'm wondering two things about it and about the consequences of modifying the default setup and configuration.
The default value for
/etc/login.defs seems to be "yes", which is reflected by the "By default, a group will also be created for the new user" that can be found in the
useradd man, so each time a new user is created, a group is created with the same name and only this new user in. Is there any use to that or is this just a placeholder?
I'm feeling like we are losing a part of the rights management as user/group/others by doing this. Would it be bad to have a group "users" or "regulars" or whatever you want to call it that is the default group for every user instead of having their own?
Second part of my question, which is still based on what I've seen on Arch and Debian: there are a lot of users created by default (FTP, HTTP, etc.). Is there any use to them or do they only exist for historical reasons?
I'm thinking about removing them but don't want to break anything that could use it, but I have never seen anything doing so, and have no idea what could. Same goes for the default groups (tty, mem, etc.) that I've never seen any user belong to.