Some chippers are sending email advertising their chips and putting long lists of collectors email addresses in the open "cc" field of their email program. Anyone who is on their mailing list receives a list of chippers' email addresses. It's not hard for someone else to send emails showing anyone's email address as the sender.

I've requested several times that my email address not be used this way in bulk solicitations. It stops for a while, but has seemed to resume after a year or so. There is an alternative: use the "bcc" or blind carbon copy feature of the email program when sending bulk mailings.