On July 13th, the Eighth Circuit held that "no knowledge" of the securities rule violated may be asserted as an affirmative defense to an order imposing imprisonment after a defendant pleads guilty to a violation of the Securities Exchange Act. 15 U.S.C. Sec. 78ff(a) provides that "no person shall be subject to imprisonment under this section for the violation of any rule or regulation if he proves that he had no knowledge of such rule or regulation." U.S. v. Behrens.