I previously did not think vote rigging was much of a threat because most machines were not online. I did not consider registration systems or other vulnerabilities that were online.
But one could hack other things, like voter registration. People likely to 'vote wrong' could be stricken from voter rolls and have no recourse in that election.
IL was "patient zero" in this investigation due to the recognition of the hack last summer. Yet, striking voters wouldn't be very effective in IL. With election day registration, voters would proceed as normal. The extra work would be for the county officials to confirm the registrations and count the votes.