First: Go here:
http://www.eq2shop.com/equipment.aspx
Second: Click on your server, and take note which items are listed on the website.
Third: Consult your friendly neighborhood broker and see if the items are listed ingame. Compare the items on the broker to the items on the website, if they are listed it should be easy to determine the name of the toon associated with eq2shop.
Fourth: Shut them the fuck down. File a petition under Product: EverQuest II General, and under Category: Community Standards Spam / Advertising.
Istiaguc of Mistmoore no longer has anything listed on the broker.