Imaginary friend names still visible to public (aka private groups)

I have set up a number of imaginary friends (aka private groups) using my friends' names and their feeds from various services (Twitter, blogs, etc). e.g. Alice Liddell at friendfeed.com/imaginary-alice-liddell

However, when visiting the group URL while not logged in, their name is emblazoned on the page, and presumably a profile image would also be visible, if I had added it. Is there any way to suppress these details? For my convenience, I'd like to see their names in my feed. For their privacy, I'd like their names suppressed for everyone else.

My current workaround is to just make up another name. Is there a way to do this properly? Any other suggestions?