Electronic voting machines
Many people are of the opinion that electronic voting machines only multiply the possibilities for fraud, and only paper-based voting is safe.
Let us start by skewering the notion that paper-based voting provides any kind of guarantee of fraud-free vote counting. Looking back at the 2000 Presidential election, in the state of Florida, Bush won by a slim 537 votes. A recount was ordered, and hordes of lawyers descended on the state to inspect millions of ballots, haggling over hanging chad, dimpled chads, and such. After a couple weeks several boxes of overlooked ballots were discovered in a closet. The circus went on for 5 weeks until the Supreme Court finally decreed Bush the winner. Fast forward to the 2014 vote for Scottish independence. After the fact, many eyewitness accounts, and even videos, of vote fraud showed up in the internet. Yet there was never even a recount.
So clearly paper ballots cannot guarantee a clean election, yet just as clearly if you want to manipulate millions of votes, the easiest way to do it is to introduce computers into the vote counting system. On the other hand, it is not computers that commit fraud, it is the people who program them, configure them, and operate them. Electronic voting fraud has been rife because the vendors and state election officials have played fast and loose ever since computers arrived on the scene. Programs written by the vendors are proprietary and not subject to scrutiny. Last minute "updates" are common, and "glitches" often happen during the counting. The programming allows the operator to override anything, and audit trails can be erased or edited. Supposedly "air gapped" computers are fully connected with the internet, and data is often sent to other continents in real time.
If anyone took election security seriously, there would be intense scrutiny of the programming by many experts, rigorous configuration control, secure audit trails, no off-site connections, and strictly limited operator intervention. Ultimately election fraud is always committed by people. With electronic voting, a lot of that people-work can be checked and verified in advance. Far fewer people are needed to do the counting, reducing the opportunities for fraud.
