Despite an overhaul of Pentagon purchasing practices under reform-minded Defense Secretary Donald Rumsfeld, an intelligent thief still can find a way to profit from day-to-day business transactions at the Defense Department, experts said Monday. The latest example of the system's vulnerability came from Marine Corps Staff Sgt. Sherry Pierre, who used a military credit card to pay for breast enhancement surgery. Pierre also made improper purchases of a car, a motorcycle and other items totaling almost $130,000 in unauthorized sprees during 2000 and 2001. Despite the abuses, the system is much improved since senior Pentagon officials announced a crackdown on...