Hashed strings can often be deciphered by 'brute forcing'. Bad news, eh? Yes, and particularly if your encrypted passwords/usernames are floating around in an unprotected file somewhere, and some Google hacker comes across it.
You may think that just because your password now looks something likeXWE42GH64223JHTF6533H in one of those files, it means that it can't be cracked? Wrong. Tools are freely available which will decipher a new proportion of hashed and same encoded passwords.