AMICUS BRIEF: Morgan Keegan v. John J. Garrett; et al. Craig J. McCann and John J. Garrett; et al. v. Morgan Keegan, Case No. 11-20736, Civil Action No. 4:10-cv-04308 Amicus Curiae of the Public Investors Arbitration Bar Association (5th Cir.App. January 18, 2012)