Developer keys (AppID) should it be hidden in some way?
The tutorials for this API leave the developer AppID visible to anyone who chooses to view the page's source. What is to stop anyone from using my AppID for their own ebay app? Should some sort of an attempt be made to stop this being visible? If so, than how is this done ?
This question comes up in the forum every couple years or so. You might want to search around for past threads. Short answer: If possible, make your app server-side instead of client-side, for best security.