People take their passwords very lightly and never update them. If that's the case then they should at least not be very simple and common so that even novice hacker can hack them.
Here is a list of very common password you should never use.
| password 123456 12345678 qwerty abc123 monkey 1234567 letmein trustno1 dragon baseball 111111 iloveyou master sunshine ashley bailey passw0rd shadow 123123 654321 superman qazwsx michael football abcdefg 987654321 asdfgh |
It is recommended that you change your passwords regularly. You can find many such password related tips
here.
