I noticed yesterday that HN is now blocked by Etisalat, one of the United Arab Emirates' two telecom companies. Their proxy server displays a page like this instead: http://en.wikipedia.org/wiki/File:Block_etisalat_3.jpg
Sites usually get blocked because a customer complained to Etisalat about their content, or because they were arbitrarily added to the SmartFilter database. I think it's the latter in this case.
I will follow up with Etisalat and let you know if I make any progress...
I'm forced to conclude we all must be doing something right.