This week "Sunday Morning," hosted by Jane Pauley, features Lee Cowan's cover story on PostSecret.com, where anonymous writers share their most private secrets with the world. Plus: Rita Braver investigates a series of mysterious deaths that were studied by author Harper Lee for a never-published book; Mo Rocca sits down with "Dynasty" actress Joan Collins; Ted Koppel visits the Broadway stage of "Network" to look at the state of TV news today; Faith Salie checks out a Brooklyn Museum exhibition of Frida Kahlo; and John Blackstone interviews Taylor Mac, playwright of the new Broadway comedy "Gary," starring Nathan Lane.