You do not have to hack any one's account to get a list of names and corresponding email address.
Just look at the mails forwarded to you or your friend. The geek in us use 'bcc' but the rest of the world will fill the 'to' with loads of addresses.
We are having festive season 'Durga Puja' and 'Dushera' now in India. I am getting lots of wishes emails and I now have tons of emails to forward 'whatever', if I wish.
Also with so many web accounts been compromised, where do you think those emails end up to.