eBay problem

I made a bid on an item today later to find out that the sellers account had been compromised. However, as I contacted the seller the fraudster has my private email address has been compromised. I got the following message from eBay:

"Dear [my-username] (me@emailaddress.com):

Our records indicate that you recently sent an email to or received an email from [seller] through the eBay email system (for example, you may have sent an email to this member through Ask Seller a Question or received an email from this member through Contact eBay Member).

Sometimes eBay accounts are used to send email solicitations for transactions outside of eBay, or to send unrelated questions in hopes that you will respond so that the other party can obtain your email address. We wanted you to be aware of the potential fraud risk these solicitations pose and encourage you to be cautious about the email you received from this member."

So my email address has been potentially compromised. Who is at fault here, eBay or the seller. and what am I to do? I monitor levels of spam against online activity and if I notice a surge, surly someone must be liable?

eBay is a pain at times.