Pwned Passwords are hundreds of millions of real world passwords exposed in
data breaches. This exposure makes them unsuitable for ongoing use as they
are at much greater risk of being used to take over other accounts.

This script offers 2 methods to check whether a password has been exposed
in an uncovered breach:

1) Online check implemented in such a way that the password to be checked
   does not need to be sent to the remote database server.

2) Local check against a copy of the pawned passwords database.

Since the local copy of the database requires nearly 20 GB of disk space
(and a download of more than 10 GB of compressed data) the access via the
online check should be preferred, if the compatible with operational and
security requirements.