All airlines have size and weight restrictions on cabin baggage, its just that very few have enforced them so people have been taking the you know what. Now a few airlines are starting to look at enforcement, about time says I.
Go to the airlines website and you will find all the restrictions on cabin baggage and if on a multi sector flight go with the lowest size for the different airlines.
Sorry but its one of my things, people with too much or oversize cabin baggage.