Pennsylvania's Corrections Department wanted to figure out why their prison officers were getting sick.  They decided the reason was a certain contraband getting into their institutions.   A form of synthetic marijuana known as K2 had been found on the flaps of envelopes and even in crayon drawings that had been mailed to inmates.  These incidents led to sweeping changes in the way mail was handled.  Fewer officers got sick, and fewer inmates overdosed.  But the American Civil Liberties Union says the changes may be unconstitutional.  Jason Bloom, President of the PA Corrections Officers Association, explains what was done and suggests other ideas to improve safety.