According to eSecurity Planet, some of the passwords are common, some not so common. Among the banned passwords are the usual suspects, such as "password" and "twitter," as well as several sports nicknames like "redsox" and "yankees." There are also a handful of banished body part passwords and several simple numerical sequences, like "123123" and "123456."
The banned passwords is just the latest effort by Twitter to help secure the microblogging site. In October, Twitter added a "Report as spam" feature.