Firefox historically had the ability to block scripts, images, and frames from being loaded from a blacklist of domains. However, these hardcore-user options where removed in recent years as they were essentially checkboxes that broke the web/browser. The code is still sitting in Firefox, though. You can add blocking rules to Firefox’s permission database and block out a few bad advertisement domains or content that annoy you or that you just want to get rid of. This tutorial shows you how to use Firefox’s built-in content-blocking capabilities. Some SQLite queries required.