Infant seatbelts should be mandatory with all airlines for the safety of the child and other passengers. We have weight restrictions for carry on luggage, which must be secured, an infant is no different. In the case of unanticipated severe turbulance or extreme altitude drop which as we all know can happen at ANY time and HAS caused major injury any unsecured object INCLUDING infants can cause serious injury to others, not forgetting the poor child. Our policy is to ensure infants are secured by a belt for take off/landing/whenever the seatbelt sign is on. I instruct even frequent travellers of the operation of the belt, to ensure that in an emergency and we need to evacuate they unfasten BOTH belt buckles. I also insruct the parent to hold the infant forward facing for take off and landing due to the brace position as the baby will then also naturally bend forward. So many times I have seen infants sitting facing the parent and think if the parent must brace suddenly they are going to snap the child in half. From the recent occurances of severe turbulance and altitude drops wouldn't you feel more comfortable with your child secured. If a plane can suddenly drop 400ft, pax injured by falling/flying luggage, where is your infant going to end up unless secured by an infant seatbelt. We are much more at risk of severe turbulance than experiencing a crash landing/takeoff.