on a Linux system there are lot's of users by default: daemon, bin, sys, games, etc.
According to my /etc/passwd most of these users have a shell assigned (/bin/sh) which seems some kind of insecure to me. My naive thinking would say: Only give those users a shell that may login to the server.
Is my thinking wrong?
If not completely wrong: Can I disable the shell for "daemon" and "www-data" without having side effects (e.g. the system wont start or the Apache PHP cannot excute system calls)?
Added: My distribution is a Debian Squeeze.
Thanks for your hints!