Here is a beta website called CVfox that could help you find not only online bios on linkedin, but online resumes too.
CVfox was created by Donatello Tomasso. I believe he recently launched this beta a month ago for the public & professional recruiters.
CVfox does three types of searches – body search, title search, and x-ray search. It first defaults to doing an x-ray search first for bios/resumes. So you can or may even refine your search by then clicking body or title by hitting the refinement tabs after you’ve run your initial search.
Try it out and see if you like it.