Increasing numbers of Yahoo mail passwords appear to have been compromised; I don’t use Yahoo [although in a historically stupid move, I have multiple email addresses from multiple providers including hotmail, gmail, my ISP and my own domain ]. Anyway, I have been getting an increasing number of spam emails from friends and acquaintances with Yahoo accounts. Not from any other source. I have been multiply spammed from multiple yahoo accounts this year, but from no other provider. The conclusion I draw from this is that either Yahoo has had its password file compromised and the spammers are slowly working their way through it, or it has a significant hole in its security, or there is a focussed piece of malware out there harvesting Yahoo passwords.
Either way, I would strongly recommend that anybody who uses a Yahoo email go and change their password, make it computer-complex (i.e. long), write it on a Post-it and stick it next to your desk (at home – not in the office where everyone can read it)
WHAT! I hear you cry. Why do THAT! You’re mad! Well, no. Brute force attacks are rare, and they will generally use standard dictionary words. I hate to tell you, but hackers know you replace E with 3, A with 4 and L with 1. So your password of AFR1C4 it as much a dictionary word as AFRICA to a computer. [ If you want a really hard-to-crack, easy-to-remember password, I suggest you refer to this XKCD cartoon http://xkcd.com/936 ]
The likelihood is that your password will be compromised by malware and not brute force attacks, in which case it doesn’t matter how complex it is. The chance it will be compromised by a burglar looking in your desk drawer is very low indeed (although people with teenage children need to be a bit more cautious.)
And change your passwords occasionally – at least once a year. How many of you out there have 2 or 3 different passwords that they use everywhere? A (seemingly) complex one for your bank account and “password” for your forum accounts? And you have NEVER changed them as it would mean changing 200 accounts and it’s too much like hard work? Thought so. One day you will be pwned by the hackers.