To avoid being hacked and having your ebay or paypal id hijacked. There are a few simple rules you need to follow:-
1) Never click on any links within the email. Always go to the site and check if you have issues there. I.E... if you get an email saying to update your information on paypal and they have a link for you to click, this link will defiantly take you to another spam site that looks like paypal but isn't. It will be a hacked site where it store all your key strokes. The best thing to do here is log onto paypal directly and check if they want you to update the info.
2) If you get emails from ebay stating the member has questions, never reply to questions from the email, go to ebay and check the mails there.
3) Always change your passwords regularly and have them mixed caps.