File Permissions

["Insane Boi" <insaneboi@gmail.com>]

Unique question, Pidgin (aka gaim) has some configuration files.  I
would like to have these configuration files remain
untouched/unmodified, but readable.  I am running pidgin under a normal
user account.  Here is what I tried:

chmod 004 file.xml
sudo chown root:root file.xml

Launch pidgin as user -> In theory, pidgin would be able to read the file.xml, but unable to modify it.
After pidgin launches, file.xml permissions become 600 owned by user:user and can be modified.

I don't understand this, as since the file is owned by root, and
the user has no permissions to modify the file, how can a program
running under that user's account modify and change the file
permissions?  Shouldn't the file permissions prevent the modification
of this file?

Thanks.