E5JBK7UJPT
We don't know how effective their enforcement of the rules are. Maybe 99.9% of listings for banned items are properly removed and what we see are just 0.1% of a very large number. I would say 99.9% is a rate that most people would say is effective. Would you say the rule enforcement is effective if it catches exactly 100% of violators?
> GET https://api.pwnedpasswords.com/range/{first 5 hash chars}
The service is only receiving the first 5 hash chars and thus could not collect your password.
Or you could read the javascript code of the page when you visit it.
> var i = sha1(n).toUpperCase(),
> r = i.substring(0, 5);
> $.get('https://api.pwnedpasswords.com/range/' + r).done(function (n) ...
Or you could download the file and check it locally.