[blackflame7001]

Your comment makes no sense in context with the original article. Why would someone spend all the time and effort to hack voting machines when they can just walk up look at the list and pick a name without a signature and say yup thats me. Ive worked at a poll it just a list with peoples names sitting on a table

[tomjakubowski]

Those attacks don't scale at all and could only be a concern for local elections in small towns and the like.

[blackflame7001]

Neither does machine tampering because they are not networked.

[Nerdfest]

One person with a USB key can change many votes on a single machine.

[mikeash]

Because you have to be physically present in order to do that, and nobody wants to risk getting thrown in jail if they pick a name that’s already voted, or that the poll worker happens to know.

[blackflame7001]

How else would you do it on a machine not connected to the internet?

[mikeash]

You could pull a Stuxnet and create malware that would spread over whatever devices are used to program the voting machines. I believe they typically just use standard USB thumb drives, and are notoriously insecure.

However, the article talks about "election systems" which encompasses much more than just voting machines. Voter registration records are a prime target and those are usually (always?) connected to the internet. You don't need to actually alter any votes to swing an election. Just delete or alter the registrations of some people who you know will tend to vote the other way.