Banned users can be configured in the setup file via the banned_users
setting. This is a list of user names, or PageSpecs
to ban. Using a PageSpec is useful to block an IP address.
For example:
banned_users => ['evilspammer', 'ip(192.168.1.1)'],
If a banned user attempts to use the ikiwiki CGI, they will receive a 403 Forbidden webpage indicating they are banned.