Extension:NoBogusUserpages

The NoBogusUserpages extension implements a restriction that allows only privileged users to create userpages for non-existent users. With this extension installed, new page creation at the root level of the    : namespace is blocked unless the creator's username is the same as the desired page name or the user has been assigned the createbogususerpage right (see user rights below for how to do that). Without this extension, anyone with the right to create pages in the user namespace can create bogus pages for users who do not exist on the wiki.

User rights
Allows users to create bogus userpages. By default this is given just to sysops.
 * createbogususerpage