There were dozens of them on my most recent domestic flight.
A group of American tourists armed with full-loaded suitcases; backpackers whose giant packs whacked into the heads of anyone sitting in an aisle seat; little old ladies who needed help to hoist their mammoth bags into the overhead luggage compartment and back down again.
No one pays any attention to the carry-on luggage limits on domestic flights; no surprise given that none of the airlines makes a serious effort at punishing passengers with carry-on luggage that exceeds the "strict" 7kg weight limit.
In an apparent crackdown, Virgin Australia is ordering passengers with overweight carry-on bags to turned around and check in their bags.
I'd go further. If you turn up at the boarding gate with excessive luggage then that luggage doesn't make the flight. You do, but your luggage doesn't. You can wait for it to arrive on the next flight.
Word would quickly spread that it simply isn't worth taking the risk. Some passengers, sure, will still believe that the rules don't apply to them. Too bad.
Virgin Australia has a strict 7kg carry-on limit for all domestic passengers, including business class guests. Virgin’s website cites safety reasons for the limit, claiming that overweight carry-on baggage “may cause injury to our guests and crew”.
By comparison, Qantas also has a carry-on weight limit of 7kg per piece but allows each passenger to bring up to two pieces of carry-on luggage. Both Qantas and Virgin Australia also allow an additional “personal item” to be carried onto the plane, such as a laptop computer, handbag or book.