Look in /etc/sudoers to see if there is a group setting. It will look like this<br><br># Members of the admin group may gain root privileges<br>%admin ALL=NOPASSWD: ALL<br><br>As long as that user is listed in /etc/group, in the admin group he'll be all set.
<br><br>Do you mean he changed all the files so they are now in the group 'users' ?<br>Are there group definitions in the sudoers?<br>