I'm surprised that there is much concern expressed about securing luggage because I've been travelling extensively for very many years and have never ever bothered about locking luggage. For one thing I've always thought that security might need to open it when it's outside my sight and in any case I can't be bothered with messing about with locks. On the other hand I don't put anything of high value in checked luggage. Any valuable items I keep with me as hand luggage.