We’ve just had a new plugin received into the WordPress plugins directory – “No Weak Passwords”.
This plugin does one thing, with no fuss – it forbids all of the 3546 passwords from OpenWall’s “common passwords” list. That list was put together using the public data from several break-ins to large sites. It is thus a statistically sound list of passwords that very man people are using, not knowing how easy they are to guess.
If any of your existing users are using one of those passwords, then next time they try to log in it will send them to the link for resetting their password and getting a safer one.
We definitely recommend you install it on all your WordPress sites. Just log in to your WordPress dashboard, click ‘Plugins’ and ‘Add New’, then search for ‘No Weak Passwords’. Or get it by downloading from here: http://wordpress.org/extend/plugins/no-weak-passwords