As we've been learning, they're just poorly engineered and tend to break a lot," Simons said. "They're also insecure, so it's possible to insert a virus.Former ACM President Barbara Simons discussing voting machines, security, and the possibility of Internet voting, at the University of Oregon
I remember the last parlamentary elections and me standing in front of this head-high apparatus with lots of knobs. One of it had a label "Invalid Vote". (Source)