Firefox tracks phishing attempts

I normally have no problem weeding out phishing attempts, but today I inadvertently clicked on a mail (not a link) which opened a phishing page in my browser. Firefox was right on it, however, and this was the result:

Firefox phishing warning 

I rather like this functionality – which I didn’t even know Firefox had – and I really like the design of the warning: Shade the offending page, display the warning prominently, and give the user the option to decied (both for this and, optionally, for the future) whether this really is a phishing attempt or not.