Sure am sorry if you got some SPAM from me over the weekend or on Monday. I found a whole in Yahoo.com's email system. There are actually several of us that discovered the problem at about the same time.
The exploit allowed someone with a Microsoft Outlook email program to "sync" or synchronize the Outlook mailbox with any Yahoo email user that had sent them an email from their yahoo.com email account. Although yahoo had originally intended this to be of use to people who wanted to synchronize their yahoo address book with Microsoft's Outlook for people that used both, the exploit was fairly easy to exploit.
Flicker, Facebook, LinkedIn, Classmates and other services were also vulnerable.
The problem is solved for me and I apologize for security breach and the resulting emails.