Of course it is. It is meant to intimidate people who would bus in people and then pay them to vote (here), vote twice (here), vote as dead people (here), register their pets to vote (here), vote as cartoon characters (here) and to vote as famous football players (here) not to do that!
Uptake Video – More than a dozen billboards stating “Voter Fraud is a Felony; up to 3 1/2 years & a $10,000 Fine” have been put up in Milwaukee neighborhoods leading up to the 2012 presidential election.
This is not the first election cycle the billboard space has been bought by an unknown group, known just as a private family foundation. The same billboards were up in the 2008 election cycle…
Why would you be upset with people not wanting that to happen, unless that is exactly what you wanted happen?