Actually, Jess, this site has been down for a while. Take a look at the date: Oct. 11, 2001.
I remember when this got taken down. It was because a follower of Bin Laden's had pulled a picture off the Internet of Bert with Bin Laden, and put it into a photo collage. (The Al-Queda supporter apparently had no idea who Bert was.)
I've heard conflicting reports about whether or not this photo was on the "Bert is Evil" site, but it was definitely inspired by it. When he saw known terrorists and murderers supporting their leader with a photo that would fit in on his website, he was horrified and shut the site down.
Personally, while I understand his disgust and applaud his decision, I found it quite amusing that the terrorist/supporter had unwittingly put a cuddly Muppet on his sign. It was like the presence of Bert made a mockery of the whole sign. A brief, shining bit of humor during those dark times.