In recent news reports, there has been discussion that
explosives can be detonated with very small voltages,
enough from an iPod or cell phone, possibly even from a
watch. These items are therefore to be banned or remain
banned where they have been.

But where's the logic in this? I assume the electric
shaver sockets in the toilets can be disconnected.
However, there are still the lights. And many other
sources of power you could get to given a few
minutes in a locked toilet....

It seems to me that stopping methods of detonation
being on board is going to be very hard. You really
have to ensure explosives (liquid/plastic/...) don't
get on board?

All it takes is a bit of flint and a bit of steel and a little practice. Once politicians wake up to the fact that we are never going to be 100% safe and that we never were 100% safe perhaps things will get more sane. Unfortunately, I don't see that happening.

Someone also raised this issue in another thread. It's easy to make a detonator--bad people, that's what should be hunted.

What logic? Why would you expect there to be any logic in it? This is aviation security we're talking about, after all!

No, there's no logic in it -- not as a long-term defense, anyway.

If there is specific evidence that the attackers were specifically planning to use camera flashes rigged-up as a makeshift detonator (say), then it might make sense to ban camera flashes for a few days as a short-term measure. For instance, such a step might cause any would-be terrorists to postpone their attack and come up with a new plan rather than trying to adjust on the fly.

However, as a long-term defense, it is clear that this is an arms race where the terrorist will always win. The defenders have to make the first move (i.e., specifying what is banned). The terrorists can then respond to identify and exploit any gaps left in the defenders' policies. The terrorists will always win that battle; there is no way to ban everything that could be used as a detonator.

So while it might (arguably) make sense to ban this stuff for a few days for ex-London flights based on very specific intelligence, it would make no sense whatsoever to maintain this as a permanent policy.

The arms race analogy is exactly correct. This analysis exposes the fallacy in concentrating on things and ignoring people. Very many things could be used as detonators. If someone is trained, he could likely use a watch as a detonator. Is British Airways going to ban watches?