Won't be the last. We only lose what we don't backup and Yahoo is known to remove accounts. There are no Yahoo folk here and we get SCAMMERS that offer to fix your issue (operators are standing by to take your CC.)
What's going on is for them to answer. On your end, it's all about the backups.
My email address has not been recognized by Yahoo for 2 weeks. 1st response from Yahoo was about a server issue. Today I was told that it had been taken down due to abuse, but they couldn't tell me what was meant by abuse. They called back later and said it was because account was delinquent --- but it isn't, and another email address on the same account is fine. Nevertheless, they connected me to ATT collections, who said "They said WHAT?" So they obviously knew nothing about the account being dissolved at their end. I have 15 years of records there. When I sign in through Yahoo, it says the email address is unknown. When I logg on through att.com, it says the email address is not found on the Accelerator. Does anyone out there have a clue what's going on?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic