A yearlong study by the nonpartisan Brennan Center for Justice found that the vast majority of electronic vote-counting systems deployed across the United States can be manipulated by hackers:

Most of the electronic voting machines widely adopted since the disputed 2000 presidential election “pose a real danger to the integrity of national, state and local elections,” a report out Tuesday concludes.

There are more than 120 security threats to the three most commonly purchased electronic voting systems, the study… says. For what it calls the most comprehensive review of its kind, the New York City-based non-partisan think tank convened a task force of election officials, computer scientists and security experts to study e-voting vulnerabilities.

The study, which took more than a year to complete, examined optical scanners and touch-screen machines with and without paper trails. Together, the three systems account for 80 percent of the voting machines that will be used in this November’s election.