root password can be used with any other user

Just discovered what i wrote in the subject, any user can login with the root password.
Shouldn't be a big issue, possibly it's not a feature, so i posted here.
Sal

ok, found this on the wiki

http://wiki.centos-webpanel.com/how-can-root-login-as-a-user

so it's not a bug, it's a feature to allow root user to login as user.