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 by the Brennan Center for Justice 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. Together, the three systems account for 80% of the voting machines that will be used in this November's election. Lawsuits have been filed in at least six states to block the purchase or use of computerized machines. Election officials in California and Pennsylvania recently issued urgent warnings to local polling supervisors about potential software problems in touch-screen voting machines. Among the findings: Using corrupt software to switch votes from one candidate to another is the easiest way to attack all three systems; the most vulnerable voting machines use wireless components open to attack by "virtually any member of the public with some knowledge and a personal digital assistant;" even electronic systems that use voter-verified paper records are subject to attack unless they are regularly audited; most states have not implemented election procedures or countermeasures to detect software attacks.