The National Cyber Security Centre released a list of 100,000 passwords known to hackers. 

The list reveals how important it is not to re-use a password: the top password is "123456" and has been found 23 million times in databases of cybersecurity breaches, according to the National Cyber Security Centre. 

The top 20 include: 

1. 123456
2. 123456789
3. qwerty
4. password
5. 111111
6. 12345678
7. abc123
8. 1234567
9. password1
10. 12345
11. 1234567890
12. 123123
13. 000000
14. iloveyou
15. 1234
16. 1q2w3e4r5t
17. qwertyuiop
18. 123
19. monkey
20. dragon