We’ve only just written about an imminent government summit to sort out the problem of inaccurate satnav mapping data sending large vehicles on inappropriate routes, but now comes news of a more serious — and much more dangerous — problem.

OpenStreetMap is project set up to create a freely editable map of the world based on user contributions, a bit like a Wikipedia for maps.

Anyone can edit and use its mapping data, and since there’s no cost involved, it allows low or no-cost satnav software to made available to people that otherwise wouldn’t be able to afford it.

Recently, however, it was discovered that some contributors to OpenStreetMap have been vandalising its data rather than improving it, with such changes as reversing the direction of one-way streets in London and New York, and even adding a fake Olympic stadium.

Worse still, the malicious edits were traced to users on networks belonging to Google, which caused some people to wonder if it was part of some deliberate attempt to discredit OpenStreetMap’s data — Google runs its own mapping service, after all.

Google investigated the problem and issued a statement saying that the vandalism was the result of two of its contractors abusing the Google network and that the contractors were “no longer working” at the company.

Given the size and scope of OpenStreetMap, this attempt at vandalism is relatively minor, but it does highlight the need to pay close attention to satnav mapping data, whatever the source.

Blindly following visual or spoken satnav directions without concentrating on what’s outside the windscreen is a recipe for disaster, not least since even the most accurate mapping data is unlikely to take account of road changes made in the couple of months.