They make fraud easier. They do not make it easy. Lots of election data is public and analyzed by all sorts of people. Any big jump in turnout or shifts in the voting pattern of specific communities will be noticed and investigated even if it is just by hobbyist and journalists. Therefore the fraud would need to be incredibly widespread and only change the results subtly. Since elections are run at the local and state levels, at least in the US, it would need to be a huge operation in order to make enough small changes to accumulate to a result changing level of fraud.