I was just thinking the same as Girtbar... how can you have no weight limit on hand luggage? Surely you need to know what's going into the o/h lockers so as to not overload them?? Safety issue too.... Say the pax is a big beefy rugby player, can lift a ton... does that mean if he can lift his 40kg (albeit small) bag then it can go in the o/h??/ That's Insane!!!!
Here in Aus CASA have just clamped down on hand luggage as it's supposed to be no heavier than 7kg, as well as fit size limits.... some smaller airline have 4kg, and the amount of crap people try to take onboard is mental...
My most used line?? "Madam, I hardly think you will need your hairdryer, you tennis raquet AND all of your clothes on a 2 hour flight"