I saw an article or two the other day on a couple of weblogs (boingboing and a whole lotta nothing) about filtering software used by businesses to block users from accessing sites. One company, Secure Computing, has a product called SmartFilter. You can check URLS and see how they classify that site. Go ahead, give it a try.
Imagine my surprise to find out that this somewhat lame personal domain (ivory-tower.org) has been classified as pornography. Wow. I posted a picture of a bicycle once, but I doubt that caused that classification.
