If you visit the State University of New York's Downstate Medical Center in Brooklyn, you'll find crash barriers disguised as large flowerpots surrounding its medical school and hospital. More than 300 remote cameras and other sensing devices protect the campus. The campus police, unarmed before the attacks on the World Trade Center three years ago, now carry guns, and have received extensive hand-to-hand combat training. All employees are required to carry color-coded badges, and background checks have become much more extensive. At the center's recently-opened Biotechnology Park, a fence surrounds the parking area, as well as the building itself, with entry permitted only by remote control.