Logwatch: connection attempts using mod_proxy

It actually means the opposite to what you suggested: the person in Taiwan accessed (or attempted to access) eBay via your server. It means that someone was using your machine as an open proxy. Most likely they were probing to see if you had an open proxy configured. The fact that the message says "attempted" would suggest that they didn't succeed, but a bit of Googling suggests that it may mean they actually got through. What you want to do is make sure you're not running mod_proxy and you disable the CONNECT verb if you don't need them.

An article I found that might be of use is http://www.davekb.com/browse_computer_tips:logwatch_connection_attempts_using_mod_proxy:txt