Jeremy Clarkson was banging on last week about how he is public school educated and has tried to eliminate all traces of his original accent yet an expert could instantly pin down where he had been brought up from tiny traces in his speech. Same with the Yorkshire Ripper hoaxer - they could tell the town. Now obviously foreign fighters are a problem in both Iraq and Afghanistan. One solution is to try and issue ID cards, but you are reliant on not issuing them to the bad guys, the locals will lose/not carry them, they can be forged... You can take locals with you on patrol, but they are hard to recruit and harder to trust.....they can use it as an opportunity to pursue local grievances. Now obviously in Afghanistan anyone who can really only speak Arabic is toast, but that still leaves a load of people who have no lawful business in the area. Could we use accents to identify where people were brought up? Cell-phone link to a centre with humans, even GCHQ software to identify, make people talk to someone? That way you don't have to drag around a possibly untrustworthy local, and they can't see who they are dealing with, don't know where you are, and can't pursue grievances - monitoring can ensure they don't touch prohibited topics. Obviously there are plenty of displaced persons who aren't sinister, and obviously capturing the local accents would be a sod - how could you be sure you were dealing with real locals. But still, it would be interesting to be able to say to somebody, "No mate, you definitely come from Waziristan, probably the village of ......."