The router works on text-based algorithms to detect inappropriate pages. Each page and its URL are dynamically registered against known words and phrases that can trigger the blocking mechanism. There are actually several layers of filtering going on as each page is loaded. On top of that, each page is logged for a complete history. Images and Videos are screened in the same way, with their URLs and title checked against our list of keywords and phrases. In addition to the automatic filtering components, there are also user-defined filters as well. Users have access to a white, grey, and black list. You can even edit a special keyword list, that defines what the filter screens for!