Mark Steel: Beware of plane-spotters bearing pens and paper

'When you've invented democracy and the triangle, why try to understand plane-spotting?'

The Greeks seem insistent on keeping these plane-spotters locked up, and at one level there's something almost admirable about a society that can't get its head around the concept of plane-spotting. I suppose when you've invented democracy and the triangle, it must be hard to see the challenge.

The Greeks seem insistent on keeping these plane-spotters locked up, and at one level there's something almost admirable about a society that can't get its head around the concept of plane-spotting. I suppose when you've invented democracy and the triangle, it must be hard to see the challenge.

To most people, it does seem a simple pursuit. Even the novice doesn't land in Greece and say: "Now, where shall we start looking for planes?" It's not like bird-spotting, where you could creep up behind your bird, tread on a twig, scare the thing and it's gone forever. If you get close to your plane and sneeze, it's not going to panic and bolt to Naples.

Nonetheless, it ought to be apparent to the Greek authorities that the people they've arrested aren't spies. If they were spies, their prize possession would be a cigarette lighter that turns into a camera, not a thermos flask with a lid that turns into a cup.

I have particular sympathy for these convicts, as I met a group of plane-spotters a couple of years ago at Gatwick Airport. One of them was especially memorable, as he'd been to Greece with a friend, and climbed under a fence into an American military airfield to spot some plane or other, where they were both arrested.

Back then, I accepted that whatever else is true about them, you couldn't say they were boring. Who else, in the pursuit of their hobby, would take on the world's greatest-ever military machine? Even the Taliban didn't do it as a hobby. Unless they've fooled us all and they're just the extreme wing of a dangerous sports club, currently in a cave, saying: "If we get out of here, next it's bareback rhino riding."

The most obsessed DIY enthusiast wouldn't cross a troop of marines for a glimpse of their favourite rawlplug, but these boys went out in the night with wirecutters and completed their conquest.

The main gripe of those detained in the Greek jail is probably that they wanted to spend the week on a mountain outside Jalalabad, yelping "wow, that daisy cutter's being dropped from an AH49 twin engine C series". In which case, it's lucky they'll soon have another chance to see all the B-52s they've missed, in Iraq.

The other snippet I recall from meeting the plane-spotters was the exasperation with which one told me: "One day last week I waited all day for an AH to arrive, then five minutes after I left, it landed." Which makes you wonder whether the bastard pilot did it on purpose. Or perhaps there are vindictive air-traffic controllers, watching frustrated plane-spotters in the gallery and saying: "No he's still there, send the 757 from Ontario round one more time."

The reason this ruined his day was because the object of the game is to see the plane, then write down the number on a notepad. This is what has got his colleagues in Greece into trouble, notepads covered in numbers of helicopters. The Greek lawyers are complaining that these numbers are supposed to be secret, and aren't registered in air force directories. In fact they're so secret, the only place they're depicted at all is on the side of the helicopters. So the secret agent who wishes to find out the number of these helicopters has a choice. Either they go undercover as a Greek airforce pilot, gradually getting promoted to a senior rank to get access to the defence chief, then knocking him out with a karate chop before photographing the concealed numbers with a camera hidden in his shoelace. Or they could look on the side of the helicopter.

It's not even as if Greece is supposed to be an enemy of Britain. Perhaps their military feels left out, with all that's going on, and they need this to make them feel important. Maybe they give a press briefing every night where the Minister of Defence says: "The notepad network is being smoked out one by one. But there are some loose leaves of A4 with numbers on that could be anywhere within the Peloponnese, so this will take time."

Surely it wouldn't take much effort from the Foreign Office to get these poor sods released. But the lawyer for the 12 says the incident is probably a result of "increased security" demanded by the Americans since the day that everything changed.

So as long as the next terrorist feels that before he hijacks a plane, he needs to write down its number on a notepad, the Greeks have got him taped. Especially if he's planning to carry out his mission with a Tupperware box of peanut butter sandwiches and a Crunchie.

And the irony is that on 11 September, there must have been a little gathering of enthusiasts at Los Angeles airport, watching the television screens and thinking: "Oh no, I'll never be able to tick off those two now."