That is not completely true, the moderators can't fix it but the owner can. The website owner can classify the website as something that will get past most filters. For instance, KLOV used to be classified as 'medical information' when it was linked directly with the Lymphoma forums. At that time virtually no one was restricted from KLOV with the generic filtering software utilized by most companies. When it shifted to the new software it became classified as 'games and gaming'. That is when I, and many others became blocked.
At the present time I can access the KLOV forums but not the IAM/KLOV main site. Some of the links are broken, many of the linked pictures don't show up, and occasionally even the forums are blocked but it is still much better than what I had for the first few months of the new software.
Oddly, on occasion an individual thread will be blocked under the classification of 'games and gaming' but this is rare and almost always a fluff thread anyway...