Registration workers for all political parties often get paid a set amount for every person they register. A few of them create phony registrations to get a few more bucks. This does not mean that anyone will show up on voting day and claim to be fictional person whose name is on the registration. The goal is, and has been for as long as I can remember, to get a few extra bucks to live on.
It's wrong of Ohio Republicans to claim that ACORN itself has done anything wrong, much less that it is trying to steal an election.
It is possible that Republicans simply want an excuse to show up at the polls themselves, and challenge legitimate voters in order to get them to leave without voting.