I posted this yesterday, but it seems to have gotten lost amongst all those stupid spam posts... [^o)]
Over 270 million Yahoo, Gmail, Hotmail/Outlook email account names and passwords have been stolen and being sold on the black market.
So change your passwords asap. And if you've been using the same email address and password on multiple sites, be sure to change those too - and use something different than your Gmail/Yahoo/Outlook password.
Read more here.