I worked at Yahoo! during a fairly large compromise. There were about 2.1M accounts which were phished. I think Yahoo!'s an easy target because 1) they have a

I worked at Yahoo! during a fairly large compromise. There were about 2.1M accounts which were phished. I think Yahoo!'s an easy target because 1) they have a lot of email users and 2) a lot of those users are older and/or more likely to be phished. It was a nightmare to fix the compromised account and took a team about 3 months to complete.