I have not heard any problems with looking at the ad or contacting them. Quite often I contact them just to mess with them and ask them for pictures to see what kind of BS they will try to send or feed to me and then I forward the info to eBay. Just don't open any attachments or links they give you in the reply email.
The eBay ad should be fine but I'm sure eBay's servers can be hacked too.
The best thing you can do to protect yourself is leave them alone, change all of your pass words to look something like this...ab0*JJ2@xZ.....not your social security number, birthday, last name etc...and change it on a regular basis,keep the computers operating system update, Use a good firewall like zone alarm, use a couple of different good and reputable antispyware programs like adawareSE and microsofts antispyware beta, a good antivirus program like Mcafee, Norton or Computer associates and keep all of these up to date with the latest definition files.
Don't write your password on a sticky note in the desk drawers, under the mouse pad, bottom of the keyboard, under the desk or bottom of the mouse etc...If you do that stuff I can find it if I'm visiting you or you do it at work which is when most people shop on eBay, If you use a password that is related to you, your likes, favorite sport, favorite player, hobbies, mom, girlfriend etc and I know your username and some of this information I can probably figure it out....If you surf at work don't let the computer remember your password and when you are done log out and close the browser so it will hopefully dump the memory cache.