Does yahoo give facebook access to my yahoo email address book or email account?

I received an email today stating that a friend had started a facebook account and listing other friends who had facebook accounts. These were people from my yahoo email address book (contacts) and also people in the yahoo account "sent mail" I had written to once or twice who were not in my yahoo address... show more I received an email today stating that a friend had started a facebook account and listing other friends who had facebook accounts. These were people from my yahoo email address book (contacts) and also people in the yahoo account "sent mail" I had written to once or twice who were not in my yahoo address book. It looks like yahoo gave facebook the addresses in my yahoo email address book and allowed them into my sent mail.

Did yahoo do this or did someone break into my yahoo email account?
Update: p.s. If anyone is going to be insulting, like Heather was, no thanks. I think my question was clear enough. Somehow Facebook got my contact list in Yahoo. I do not have a Facebook account.
Update 2: Just found out from someone that Yahoo does give Facebook access to your address book unless you uncheck that option in Settings somewhere. Now I just have to find where that is.
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