Although I hesitate to add to the locking bins sub-discussion I feel compelled to respond to the post below. Some of the points made crystallize the different risk decisions faced by airlines, airframe manufacturers, and regulators:
Thats about all we can really do I think.
No it isn't. Ban carry on luggage. Problem solved.
Sorry but that is a short sided reaction.
Banning all carry-on luggage is the only way to bring the risk from carry-on luggage to zero. Any other option presents a non-zero risk. By choosing another option, the increased risk is being implicitly accepted as a tradeoff for a benefit, such as keeping medicines, computers, or papers with the passengers.
You can't punish the millions of people for the few stupid ones.
There's a benefit to a no carry-on policy that must be recognized -- If an accident occurs, passengers that would otherwise die are allowed to live simply because no one blocks an aisle to retrieve their bag. I fail to see how that is a "punishment". (Or perhaps you mean millions are inconvenienced by not having their bags with them to save the lives of the few who may be involved in an accident? If so, you are making the risk trade-off I spoke of earlier).
I agree that locking the bins could be a option and technical it is not a problem.
But some traveller, somewhere, in the heat of the moment, will stop in the aisle and try to force a bin open. That will delay deplaning and may contribute to a higher death toll. But like I said, it's a risk question. Evidently many are more than willing for someone else to assume the risk.
Even i'm a seasoned traveler nobody knows how somebody would react in a emergency.
This supports the point I made above about "some traveller, somewhere, in the heat of the moment, will stop in the aisle and try to force a bin open".