umask - default user settings?

[Hans <hans.ullrich@loop.de>]

Dear list, 

I am wondering, why on a multiuser system like debian the rights for a normal 
user are "rw- r-- r--", (owner: user and ownergroup: usergroup)

Of course there is a reason for this, but it is not understandable for me.


First two are clear: rw for myself, and readable for all users, i am allowing 
into my own grou. 

The last one is not clear for me. Why should I allow the rest of the world 
read my personal documents? These are private and no one else should be able 
to read them! 

So I would have expected a setting of "rw- r-- ---" for any files. 

Before someone argues, "you can change this by editing umask", yes, I know of 
this of course. 

But it is not clear for me, why it is set that way by default and not as I 
would have expected as described above.

Sure, there is a reason for this, so I will be happy, if someone could 
enlighten me.

Best

Hans