TWiki::AccessControlException web - the web which was being accessed
topic - the topic being accessed (if any)
user - canonical username of the person doing the accessing. Use   the methods of the TWiki::Users class to get more information about the   user.
mode - the access mode e.g. CHANGE, VIEW etc
reason a text string giving the reason for the refusal.
$mode - mode of access (view, change etc)
$user - canonical user name of user doing the accessing
$web - web being accessed
$topic - topic being accessed
$reason - string reason for failure
$e->{web} and $e->{reason}