Once again BJ Penn brings shame to us all

[TomK]

TYPICALLY, the ability to sue a public figure is much more involved in proof and legal requirements.

That makes no sense. How does suing a public figure mean it's "much more involved in proof and legal requirements."? What does "much more involved in proof" mean?  How about citing some case law and be done with this argument?

Please remember, you made the claim that "Typically, a public figure cannot sue or be sued for defamation.". What law or part of the constitution means a public figure typically can't be sued or cannot sue?