Volunteer
Untrained poll workers are, by and large, responsible for the security of individual voting machines. You can do your part by volunteering and being a reasonable, responsible guardian of the public trust. Keep your eye on the machines, and if you notice an anomaly, let the press know. The media aren’t good for much, but when it comes to stirring up trouble, you could do worse.
If you want to get more activist, contact the candidate of your choice and volunteer to be a monitor. Poll monitors keep an eye on polling stations and watch for voters who seem to be struggling with defective or misbehaving machines. Armed with the phone numbers of machine maintenance technicians, the secretary of state, and other people who really don’t want to get angry phone calls on election day, poll monitors can have a grand time ruining the days of people who otherwise would just sit around being self-satisfied.