People who listen to punk become or are drug addicts?!?

ok so i love listening to punk or punkish type music. Not the pistols, more like rise against, anti-flag, ignite and stuff like that and suddenly my parents tell me that if i keep listening to this stuff, they'll take away my ipod. They say that people who listen to punk become drug addicts which doesn't make any sense because the music i listen to isn't even about drugs more about human rights and politics and i completely detest drugs.