Because ALS laws are immediate and require no proof of guilt, proponents such as Mothers Against Drunk Driving argue that they are more effective in reducing drunk driving than are traditional post-conviction sanctions, and that, in any event, driving is only a privilege. However, civil liberties advocates and other critics object to a procedure in which guilt is presumed and punishment is automatically imposed by the officer; they further point out that state and federal courts have held the driving privilege, once given, to be a vested right that cannot be taken away without due process. See, e.g., "Schuman v. California", 584 F.2d 868 (1978).