enginesBlocked.php

<?php 
//Shows a big red banner to administrative users if search engines are blocked on a Wordpress site
function enginesBlocked() {
	global $wpdb;
	if (current_user_can('manage_options')) {  
		$table = $wpdb->prefix . "options";		
		if ($wpdb->get_var("SELECT option_value FROM $table WHERE option_name = 'blog_public'") == 0) {
			echo '<div style="background:#C0392B; color: white; padding: 5px; border; 2px solid #E74C3C; width: 100%; box-sizing: border-box; -moz-box-sizing: border-box; font-size: 32px; text-align: center;">Search Engines Blocked!</div>';
		}
	}
}
add_action('wp_head', 'enginesBlocked');