Standard web filtering technologies make use of databases of URLs that have been inspected and categorized under one or several content classifications to enable the category based blocking of web pages by the URL. This is a common approach for web filtering solutions built into firewalls and other network security appliances, and provides a basic level of protection against pornography, gore, hate sites, etc. with the added benefit of being included in a device already required on the network for another function (firewall, anti-virus, etc.).
The downside to URL-based filtering is that it leads to significant over- and under-blocking of content, since few web pages can be narrowed down to a single classification.
Content Quilting takes a different approach, looking in real-time at the content elements within the page and blocking only those text, link, or image elements that actually contain problematic content. The remaining page is then reconstructed for delivery to the end user, avoiding the issue of over-blocking/under-blocking and increasing the amount of web content available to the user while still providing reliable protection.
Content quilting can be performed on both HTTP and HTTPS content, and can also be used to monitor IM/Chat and Social Media activity.