How do i eliminate my Yahoo! ID name from my public profile so i don't get "junk" IMs?

Yahoo! required me to list my Yahoo! ID name on my public Yahoo! profile. Because this name is now available to anyone, i'm now getting dozens of "junk" and IMs. How do i take down my Yahoo! ID from my profile? If i can't do so, then i will have to uninstall my Yahoo! IM engine and go with another IM service.