Pranks that deserve admiration

Normally, i'm not one that condones lawless behaviour. And since my dad and people like him rely on roadway signs to protect them from clueless drivers, i understand how troublesome a breech like this is and what kind of dangers it presents to road crews and motorists alike.
But I must admit, whoever came up with this multi-state prank deserves some applause before they get fined.

In three states, Washington, Illinois, and Texas, roadsigns were hacked to display messages such as above. Some of the better ones were: "Caution zombies ahead", and "Daily lane closeures due to zombies". Although it looks like one county didn't quite understand the whole message because they put "Raptors" instead.

Natrually, my overly active imagination took this prompt and ran rampant with it.
What if these signs were common place in our lives, general warning for zombie swarms? That would be interesting!