Alerts you when you visit an unsafe website!
In the popup and options page this explains what an insecure website is. Anytime you visit an insecure website it will give an alert telling you not to enter any sensitive information. This is very important for safety because sometimes other safety features on insecure websites are easy to overlook and sometimes you need to locate them and manually enable them, which can be difficult or time consuming, instead of being enabled by default.