[Yello] list question

I was under the impression that our email addresses on this list are undisclosed - however I just did a search on AOL and found my name and email address plain as day... (a creepy guy from back in high school has emailed me, ewwwww) and this is the only way I can figure he found out... ... was I mistaken in my interpretation of our privacy of our email addresses? or am I still "challenged" as far as my computer and email literacy? I appreciate y'all's advice. I have enjoyed this list a lot.