Every state's department of transportation uses those electronic highway signs to warn of “Lane Closure Ahead” or “Fines Doubled in Construction Zone.”

The problem is, some high-tech pranksters with too much time on their hands and menace in their hearts sometimes like to hack into those signs and create their own messages. The Dallas Morning News has this story about several such instances in that metro area. (And note the last sentence in the story: It may seem like fun and games to the hackers, but the people in the Texas Department of Transportation do not find such shenanigans amusing.)