Do you have an account with Facebook ?
Have you changed your Privacy Settings for Contact Information ( http://www.facebook.com/settings/?tab=privacy§ion=contact ) to stop people getting your email address?
We use a number of providers for email services, to protect our “name”, including Google, Microsoft and Yahoo too …
Unless you have protected your email address within the Privacy Settings on Facebook, anyone importing contacts to Yahoo will get a list of these email addresses into their Yahoo Contacts!
Within Facebook, we have a number of “Friend Lists” setup, including what we call “9 Limited” – most new “friends” are added to this list when we respond to a friend request within Facebook, just until we know who they are. In the Privacy Settings, we do not allow people to see certain things – like phone numbers and email addresses – by including the “9 Limited” list in the “except:” boxes.
WE STRONGLY RECOMMEND YOU TO CREATE A SIMILAR “LIMITED” FRIENDS LIST, ADD UNKNOWN CONNECTIONS (WHICH INCLUDES FRIENDS, APPLICATIONS AND PAGES) AND CHANGE YOUR PRIVACY SETTINGS TO NOT ALLOW ANYONE TO VIEW YOUR PRIVATE CONTACT INFORMATION e.g. EMAIL ADDRESS OR MOBILE NUMBER.
Once we found this out, we did a small test and found that we could get 90% of email addresses for our friends on Facebook !! We’ve deleted the downloaded contact records.