Now when you search for certain celebrities or well-known personalities, Google may show links and icons to their social profiles within the Google Knowledge graph panel.

For example, if you search for [Barack Obama] you get to his Twitter, Facebook, Google+ and Myspace profiles. If you search for [Kim Kardashian] you get links to her Twitter, Facebook, Google+ and Myspace profiles. If you search for [Neil Young] you get links to his Facebook, Twitter, Myspace and YouTube profiles and if you search for [Kristen Bell] you get links to her Twitter and Facebook profile.

Here are some screen shots:

Forum discussion at Google+.