The ThreatPoint URL Blocker, is a browser extension that looks at the URL/Web address, analyses and redirects the request if the web site is considered to contain malicious, sensitive or explicit content.
This extension / add on was created to protect innocents from clicking links to web sites that contain sexual content. The service has been expanded to include other content as suggested by users of the service.
The ThreatPoint content service provides the database of sites, ratings, categories and whether the site is considered live or not. The browser passes the entered website to the content service which responds with the decision to block or not. If the decision to block is received the end user is redirected to a landing page.
ThreatPoint have created browser extensions that use the API. These extensions can be download from the relevant extension / add on store. Available for Chrome, Firefox, Opera and Edge.
This video shows the chrome extension in use.
Protect your family (or yourself) from accessing mature, explicit and sensitive content by using this extension.