joema
It is clear from many of these reports that the batteries were carried loose or in a way that allowed the terminals to short out, or that the electronic cigarettes were packed or carried in such a way that the activation button could be continually pressed. Some of the other devices were being used with non standard chargers or accessories. The point of sales devices used by crew members are a bit more of a puzzle, but intensive use and constant wear and tear on the devices could result in a short circuit developing in flexible cables or connectors.
So no, I do not think that all these devices were modified. I think that they were carelessly packed or used and abused over a period of time until failure occured. Lithium ion and lithium polymer batteries have a huge power density and are dangerous unless treated with a measure of respect.
Boeing, despite recent problems, are still pursuing lithium battery technology in their latest aircraft. If an aircraft manufacturer deems them safe to fit as standard flight equipment then the risks must be manageable at some level.
Carrying pallets of huge lithium cells with an unproven safety record and dubious manufacturing standards on cargo aircraft is another matter altogether. There cannot be any doubt whatsoever that these need to be subject to stingent checks and controls.
Banning what many passengers regard as essential consumer devices for business or holiday use would be pointless. Some would inevitably find their way aboard. Metal bins placed at intervals in the cabin for the containment of faulty consumer devices carried by passengers might be sufficient to migitate some of the risks. Or existing containers on board could be modified and used for such a purpose.
These batteries are here to stay and they are going to end up being carried in aircraft knowingly or smuggled aboard. The important thing is to be aware of the dangers and to be prepared to deal with the problem if an incident occurs.