Wayne and Erika Pfeiler

So today I saw these chalked all over the NCSU campus. No other message, just "Don't Worry - Be happy!" with a smiley face. As you can see, this one was placed on the side of a dumpster, which is close to my building. Others were on buildings, sidewalks, walls, streets, pretty much everywhere.

Was it national be happy day or something? It's a long time since 1988 when Bobby McFerrin had the hit song, so I'm guessing there's some other significance. It'd be a catchy way to advertise some campus event, but I'd expect some other message to accompany it, or at least a location and date or something.

Weird. Does anybody else have a clue?