After this week's controversy surrounding Lady Gaga's reportedly M15+ live show there have been calls from outraged parents to slap restrictions on future touring bands and their shows. Hardly a new phenomenon, the outraged parent has always disapproved of music that is risque or against the norm. Here we look at the top ten pop acts that have outraged parents, and why, despite the bad press, they have endured as the biggest pop acts of all time. Besides Tatu, that is...