"State of the Net.Net" » * The big password mistake that hackers are hoping you’ll make

"State of the Net.Net" » * The big password mistake that hackers are hoping you’ll make:
"Can you tell how strong a password is?
To see, try to figure out which of these four are a pushover for hackers.

Zdhkqjbu83
74Xmbgdapw
Bmukwes3901!
lw;62v74y

Spoiler:
They’re all an easy mark for hackers, even though every one is 9 or more characters long and contains a mix of both letters and non-letters.
How can such apparently strong passwords be so weak?
The short answer is that they follow some of the most common patterns of composition that people use to create passwords, patterns that weaken them."