The algorithm was able to guess these passwords by using two key data points: your sister passwords and personally identifiable information.
Sister passwords are any passwords you use for other accounts. So basically all those passwords we talked about before could have a hand in making your other passwords weaker. If you use similar passwords for multiple accounts then that’s not helping you.
Personally identifiable information is information you enter into other websites like Facebook and Twitter. So if you tweet something like “Go Broncos!”, it’s able to gather a lot of relevant information from that alone.
As we put more and more information about ourselves out onto the internet, the internet in turn has a better chance of getting to know us and can derive our password from the given data.