Code-Snippets-Functions/Execute a function on a child site/WordPress/block-user-enumeration-attempts.txt

function wp_block_user_enumeration_attempts() {
    if ( is_admin() ) return;

    $author_by_id = ( isset( $_REQUEST['author'] ) && is_numeric( $_REQUEST['author'] ) );

    if ( $author_by_id ) 
        wp_die( 'Author archives have been disabled.' );
}
add_action( 'template_redirect', 'wp_block_user_enumeration_attempts' );