I know I've had a problem with it before. I went out of town a few weeks ago to visit my family and my only connection to the world was through my parents filtered internet provider. Their service classified AO as a criminal behaviour site and wouldn't let me access it. I filled out a form to have someone take another look at the site, and I explained that it wasn't pro-hacking, but rather anti-hacking, but I never got any answer back.