Punk Music with a political motivation- often people who want to change the world feel that they can't deal with what they see a corupt political system and so they choose to express their outrage though music.
This type of music can be inspiring and intelligently written or it can be mindlessly screaming that the whole f-ing world is sh*t.
It hasn't got to be about drugs. It can be about war or ... well war or drugs.
Anti-flag are a political punk band strongly against the American war in Iraq so they write songs about it in the hope that more young people will become politically aware and vote for a more competent leader next time around.