Problem with 2004 Gsxr 600....?

My bro just bought a bike and when turning a corner, right or left, it feels as if the bike is turning too far. it's like a car with power steering. Im not quite sure how to explain this but the bike wobbles when you turn corners. Even when you drive in a straight line, it's easy to turn the handle bar right or left, feels like it's loose or something. Does anyone understand me or know what's going on? Please help...........