It would be a harder path to travel. A case could be made that it creates a public hazard in the means similar to shouting fire in a crowded room but you do make a good point.

Ideally the news agencies would come to the same gentleman’s agreement they made in the 90’s when reporting on celebrity suicides was determined to create copycats.

Maybe instead of laws we could establish guidelines that competing news agencies could use to call to question the morality of stations reporting on mass shootings similar to those released on suicide coverages

http://abcnews.go.com/Health/story?id=117288&page=1

Either way it would be a good conversation to have with both the government and the media.