So much information that we use and access on a daily basis is protected by passwords. But how do you know if that password is secure and unique enough that it cannot be easily guessed?
There are many programs that are used by malicious hackers to attempt to break into password protected services. These use what is called a dictionary list or word list; simply a text file with one word per line, which the program reads through, trying each word in turn as the password. If your password is in a wordlist possessed by the attacker, it will be broken.
CB Services has been collecting and appending wordlists, building one of the biggest wordlists available on the Internet. This wordlist isn't currently available for complete download, although it may be at some point in future. Currently, however, you can enter your passwords and passphrases, and see if they are in the list.
Now, if you're security paranoid, like me, then you'll immediately suspect that this is just a way to collect people's passwords. If you're not security paranoid, you should be, because it could easily be that.
But it's not. If it makes you more comfortable, enter a completely random garbage series of characters, like "#W$Tgwerv#$B#q" This shouldn't be in the wordlist, so it will return no hits. Then, when you know it doesn't say everything is in the wordlist, you can enter your favourite password and see if it's in a dictionary list somewhere. If you get results, then you might want to rethink how you pick passwords.