Threats might be credible, but there's a more insidious risk in banning laptops and tablets from flight cabins.

When I travel, I carry gadgets. It's a function of my job as a technology writer, but I'm far from unique in this respect. Indeed, on any given plane you can expect to see as many folks staring at tablets or laptops as those folks desperately trying to get the touchscreens embedded in the backs of their seats to actually work.

So when the news emerged that US and UK authorities were planning to ban any item larger than a regular smartphone from in-cabin use, insisting that they have to be stowed in checked luggage instead, my internal alarms went off.

The cited reason is the prospect of terrorist groups building bombs in the battery compartments of laptops, but there's a larger safety aspect that this ban seems to merrily skip around. The supposed threats could be 100 per cent credible, but that's not my concern.

Anything in checked baggage is subject to significant stress and strain as it travels from conveyor belt to plane and off again. Transport staff are overworked and apparently lacking in proper sleep. That's not a recipe for your luggage to be treated with kid gloves. The pressure to take off and our insistence on lower plane fares pretty much seals the deal as it relates to how baggage is handled.

What it also represents is a risk to passenger safety. Do you know what doesn't particularly like being bumped, dropped and subjected to pressure from an oversized suitcase landing on it? Gadgets with lithium ion batteries in them, and these days that's essentially every gadget, irrespective of size.

It's precisely why, if you've flown recently, airlines tell you not to try to recover your phone from a seat if you drop it down there. They don't care much about your phone, but they don't want the plane going up as the result of a smashed battery catching fire. It's also (and this adds more salt to the wound) why most insurance policies won't cover your laptop if it's smashed in checked baggage en route.

The timing is especially interesting given that it comes just a week after the The Australian Transport Safety Bureau issued a warning relating to the safe use of in-flight gadgets. That followed an incident where a passenger on a flight from Beijing to Melbourne had her headphones catch fire.

We don't know (and the ATSB rather specifically won't say) much more than the fact the headphones went up. Paradoxically, it's a good thing it happened in the cabin.

No, I don't want to be in a cabin filled with smoke and plastic fragments either, but the same issue happening in cargo could go undetected for much longer with far more tragic results. You wouldn't need a bomb in the hold if somebody's overstressed laptop or tablet starts a cargo fire and it doesn't get spotted rapidly. That's presuming that those laptops aren't old or faulty in some other way, too.

Even the rules around gadgets are poor. It's not just laptops. Any electronic device larger than 16 centimetres long is prohibited. Straight off the bat, if you've bought Oppo's new R9s Plus or HTC's U Ultra phones, you can't take them in the cabin with you, because they're marginally longer than 16 centimetres. Are airline staff really going to stand at boarding gates with slide rules checking new phone models?

The statistical reality here is that while incidents of catastrophic battery failure are remote given the millions of gadgets in use every day, they do happen. Sadly, there are already documented instances where the combustion of lithium ion batteries have taken down planes, not helped by the fact that this type of fire is much harder to control than conventional combustion.

At the start of the year, HP recalled more than 100,000 laptop batteries due to fire risk. Most major laptop manufacturers have gone through those kind of recalls in recent years, although none of them set out to make laptops that doubled as fire starters. For any recall, some folks simply don't get the message that there could be a safety risk with continued usage.

Logically there's probably an HP (or other brand) laptop or two bouncing onto a flight near you right now with a battery that represents a very simple non-terrorist risk. There's also probably one or more older, already overstressed laptop or tablet where the battery risk comes from existing damage, or damage incurred by baggage handlers en route.

That's a recipe for plane fires that you can't easily detect or deter, so while you might catch a few terrorists along the way, you could be putting the public at risk by doing so.

Alex Kidman is tech & telco editor at comparison site finder.com.au.