The 2000 elections in Florida prompted a hysterical rush to change over our voting systems to something more "high-tech", which in this age means WITH TEH KOMPUTARS! OMG IT WILL R00L!! It was immediately obvious to myself, and to basically all reputable computer scientists, that computerized systems would only provide new opportunities for both inadvertent mistakes and deliberate abuse, unless great care was taken with the machines' design and implementation. Of course, in our current political climate, it wasn't hard to anticipate that crony capitalism would probably triumph over transparent democratic process and sound engineering practice. The links in this MeFi thread document the fiasco in detail.
UPDATE: Kos has more, including the following on Diebold's machines:
In its study released Thursday, Science Applications found 328 security weaknesses, 26 of them critical, in the new computerized system, which is supposed to be in full operation by the March presidential primary election. State officials said they will correct the problems identified in the Science Applications report and have the system ready by then.