private static function makeSafer(&$safe, $letter)
    {
        // To properly obfuscate the value, we will randomly convert each letter to
        // its entity or hexadecimal representation, keeping a bot from sniffing
        // the randomly obfuscated letters out of the string on the responses.
        switch (rand(1, 3)) {
            case 1:
                $safe .= '&#' . ord($letter).';';
                break;

            case 2:
                $safe .= '&#x' . dechex(ord($letter)).';';
                break;

            case 3:
                $safe .= $letter;
                // no break
        }
    }