"This radical islamic group should be BANNED! I'll bet they don't sing the anthem in muslim schools"
Would be a poor reason to ban an organisation and would be non -democratic , if people are not proud to sing the national anthem then they should not have to , but best to find the underlying reason why they are not proud .
If they are not proud because they have allegiance else-where then maybe Australia needs to be involved in helping the un patriotic to be repatriated to else-where or where-ever .