Random question about tv shows?

okay so i was thinking a lot one day and a question popped up into my mind. so you know those shows like bones, csi miami, csi new york, etc.....right? theyre about murders and stuff so i was wondering, isnt it a bad thing tat there are shows like those? i mean, wat if there are murderers or bad people watching it? theyll get ideas on how to kill people? even though i like watching those shows, i still wonder. so can someone tell me the "pros" and "cons" of shows like the ones described?