server config, <VirtualHost>, <Global>
1.1.3 and later
The AnonymousGroup directive specifies a group-expression to which all matching users will be considered anonymous logins. The group-expression argument is a boolean logically ANDed list of groups to which the user must be a member of (or non-member if the group name is prefixed with a `!' character). For more information on group-expressions see the DefaultRoot directive. If the authenticating user is matched by an AnonymousGroup directive, no valid password is required, and a special dynamic anonymous configuration is created, with the user's home directory as the default root directory. If a DefaultRoot directive also applies to the user, this directory is used instead of the user's home dir. Great care should be taken when using AnonymousGroup, as improper configuration can open up user home directories to full read/write access to the entire world.