Elections officials in several states are scrambling to understand and limit the risk from a "dangerous" security hole found in Diebold Election Systems Inc.'s ATM-like touch-screen voting machines. The hole is considered more worrisome than most security problems discovered on modern voting machines, such as weak encryption, easily pickable locks and use of the same, weak password nationwide. Armed with a little basic knowledge of Diebold voting systems and a standard component available at any computer store, someone with a minute or two of access to a Diebold touch screen could load virtually any software into the machine and disable...