AA (In case you hadn't heard)

Arthur Andersen conviction overturned
http://www.cnn.com/2005/LAW/05/31/scotus.arthur.andersen/index.html
"At issue for the court was whether the wording of jury instructions were improperly vague. Maureen Mahoney, attorney for Andersen, told the justices the government used improper legal definitions that made it impossible for the defendants to get a fair verdict."
"The disagreement hinged on whether the term "corruptly persuading," contained in federal criminal statutes, in this case means "having an improper purpose ... to subvert, undermine, or impede" when it relates to obstruction of justice and witness tampering. The various legal standards of "criminal intent" were at the heart of Andersen's appeal."

"Chief Justice William H Rehnquist said the instructions were too vague for the jurors to decide correctly whether Andersen had obstructed justice. (from Andersen's Enron verdict quashed, http://news.bbc.co.uk/2/hi/business/4596949.stm)"

Arthur Andersen and Enron. Remember them? - Vox