People have been committing violent and homicidal acts since there's been people basically. If all it takes is a heavy metal, hell, any kind of song, movie, TV show, WHATEVER, to get a person to do something violent or psychotic, then I think that we can safely assume that the person was fucked in the head to begin with and would've pulled the crap anyway. After all, Malcolm McDowell's character in "A Clockwork Orange" was into Beethoven! Even if someone into Beethoven was to commit a heinous act in real life, I seriously doubt that too many people would be clamoring for orchestras to stop playing his work. Of course one can never be too sure with some of these "moral crusaders".
The people that accuse heavy metal of causing violent or otherwise socially unacceptable behavior often forget the music that they themselves grew up with. My grandparents kept getting told back in the 1920's that jazz was ruining America's morals and causing people to violate that "most wonderful and noble experiment" that we all know and love(NOT!) as Prohibition. My grandfather wouldn't let my aunt watch Elvis the first time that he appeared on The Ed Sullivan Show, saying that he was a bad influence.Elvis, Chuck Berry, and Jerry Lee Lewis were basically the equivalent of heavy metal in their day, and people accused them of encouraging, among other things, juvenile delinquency and race mixing, and said that they should be locked up. Yet, we've done just about everything but make Elvis' birthday a national holiday! People bitched when the Beatles came over- my 6th Grade PE and Health teacher hated them because they brought back men wearing long hair. Us older headbangers definitely remember parents, teachers, priests, ministers, etc., griping about how Kiss, Black Sabbath, AC/DC, etc., were luring us toward Satan. The Principal of Central Junior High School(My junior high, 1976-1978) wouldn't let anyone wear Cheap Trick T-shirts because he said that Cheap Trick was the name of a prostitute! Like, GET A FUCKING GRIP PEOPLE!!! There are far, far bigger problems in this world than whether or not a certain band or music genre encourages whatever behavior.
If these anti-metal people somehow succeed in getting metal banned or restricted, I bet that they'd go after [c]rap music next for encouraging people to smoke crack, drink malt liquor, slap "ho's", pack 9's, and be "gangstas". Of course the outcry from the Black community would possibly be at least as potentially violent as it was over the 1992 Rodney King verdict.
After that, some of these "Public Crusader" types might feel encouraged go after country/western for encouraging adultery, drinking(I sure hope that nobody SERIOUSLY thinks that Garth Brooks' Friends In Low Places is about drinking lemonade- STRAIGHT!), beastiality("That thar sheep looks mighty hot Cletus"! "It sho' does, Billy Ray"!), or inbreeding("Ah bets I could git under them thar sheets with mah cousin Nelda Sue if ah gits her drunk enuff"), or even implying violence("I gots me sum respect wid dat dar shotgun rack in the back of mah pickup"). Hey, my old paper route boss(A Biblebanger) thought that EDDIE RABBIT(!!) was TOO RADICAL(heavy) for him! Imagine the outcry from country and western fans griping about censorship if that were to happen- something one doesn't currenly hear much about in country/western.
Pretty soon these self-appointed "Guardians of our Public Morality" could find or think up some reason to after children's music("Ernie and Bert encourage homosexuality!! HALLELUJAH!!!!"). Of course I'm sure that the Teletubbies would have the first priority on their hit list if that were to happen. As long as these sanctimonious, self righteous assfucks started with Barney and the Wiggles, THAT might not be so bad- I absolutely can't stand those characters!! Eventually these Biblethumpers, "Moral/Public Crusaders", and other assorted self-righteous fartknockers would find their way to getting rid of all classical and opera, until MAYBE only Gospel music(IF that) is allowed and everything else is banned, just like the Taliban did.