Rocker Dave Matthews has urged the U.S. government to do more for traumatized soldiers coming home from Iraq. A recent task force survey found that more than one-third of troops and veterans suffer from problems such as traumatic brain injury and post-traumatic stress disorder. And Matthews is so unhappy at the findings he has asked fans to sign a petition, which has 23,000 signatures so far, that asks Congress to investigate the claims. He says, "It just struck me as a profound injustice that someone who had given so much of themselves and clearly showed such a quality of personality that the gratitude we're showing them was basically a dishonourable discharge."