Google Reader’s tag sharing feature allows people who use Google Reader to satiate their RSS appetite to share certain tags with anyone and everyone else. I’ve started a system where I use the first name of friends with whom I want to share items. It saves me from having to ask them to sign up for del.icio.us, and all I have to do is send them the link once and request that they bookmark it.

After noting that the URLs for these “nametags” had a similar structure, I decided to replace the name with another tag of mine, the “mac” tag. I was immediately taken to a page that had all my items that were filed under “mac.” There’s just one problem. I have never told Google Reader to make that tag public.

Is this a bug in Google Reader’s implementation, or is in just an artifact that occurs as a result of the social nature of the webapp? Surely Google should not mislead its users into believing that certain pages are not public when in fact anyone with whom you have shared a tag link can access your other tag pages.