When was the last time you (affiliate program owners) have placed a virgin email address in your member database on your server to see if your member's email list has been compromised? Bet when you do it, you will see spam on those emails in 3 to 5 days ;)
Got some serious hackers selling off member's lists fresh from hot small to huge sponsor programs DB's and the ones who buys these lists are some of the biggest affiliates in the biz.
Seed fake members in your DB and then thank me later for warning you.
