If your Google Reader account is linked to a Google Account that's on Buzz, you get all this sharing whether you want it or not. The solutions seem to be: 1) disable Buzz; or 2) create a separate Google Account specifically to use with Reader.
I think he's complaining about the other direction--- other people's feeds being shared with him, polluting the "All Items" view with items shared by his Buzz contacts, while he'd rather just see his own subscribed feeds there. Apparently you can't turn that off without disabling Buzz entirely.
