Voter fraud has been a problems since the time elections began in the United States. Just as technology allows a single person to reach millions of people easily, it also allows one person or a small group of people to steal from millions of people. They can steal votes with the same or similar technology.
Voting fraud is still a big problem. Most voters now use machines to cast their ballots. This has opened up the potential of hackers manipulating voting machines to change election outcomes. Voting machines have been proven vulnerable to hacking. Therefore, the chance of voting fraud is still high. Proper checks and balances are needed to ensure that every vote is cast and counted fairly.
Yes, voting fraud is a big problem and everything that can be done to prevent it form happening should be done. There are a number of reasons that a hacker may want to hack the current election. There is a lot riding on the candidates in the election. Furthermore, a hacker can get famous just by being successful.
There is simply no evidence that wide scale voter fraud has ever taken place in a modern U.S. election. Hard copies of electronic ballots can be produced and retained against the possibility of machine error or a suspicion that the electronic results were tampered with. This should be more than sufficient to ensure a fair and accurate vote count.