Coldplay frontman Chris Martin has defended his outspoken political beliefs, insisting the band feels obligated to discuss the world's injustices with their fans. The singer tries not to come across too preachy, but admits he can't resist using their celebrity status to promote good causes. He says, "We just say those words (fair trade), and make sure people look it up themselves. "When people take pictures of us, we feel like we could start advertising something we care."