At least one Optical Scan machine (from Sequoia Voting Systems) was so poorly calibrated duing the election earlier this month that it will require a recount of thousands of ballots in Napa County, possibly reversing the outcome of some elections. Kim Alexander, president and founder of the California Voter Foundation noted it's a good thing that there was a paper trail. If they were using strictly electronic ballots "they might not have ever known there was a problem at all".