This SMK stuff sounds more like fables and urban legends. If anything maybe there was a first instance where a murder took place, a smiley face was found near the scene, and then somebody read about it and did a copy-cat crime. If there was an instance where 30+ murders took place like they say with the same circumstances there would be more emphasis on the investigation. From what I have been googling, sounds like a bunch of theory and boogieman tales...
Some of the stuff is kinda creepy. There seems to be some connecting clues to different 'drownings'. Oddly enough many of them based back to Duluth drownings. Maybe it is a serial killer but who knows. some things just seem weird.