Although if you read the links the OS do put in false details, as the AA discovered to their expense, it's just they're very subtle. The exact placement of a small thicket, the width or curve of a road, nothing that makes the maps misleading but enough to identify the origin if copied.
It was the TV programme I was apologising for, not the fact that OS deliberately put false detail in to catch copyright thieves...
The dispute—which had been rumbling on for some time, first surfacing in the courts in 1996 and dating back as far as 1990—ended when the Automobile Association agreed to pay twenty million pounds to the Ordnance Survey in a settlement agreed just hours before the case was due before a judge. Centrica, the multinational utility which acquired the Automobile Association in 2001, made a statement that “the AA’s processes were not as robust as they should have been,” while stressing that they had “genuinely sought” to create their own maps from scratch.
The case rested on a series of unique fingerprints within the maps themselves described by the Ordnance Survey’s chief executive Vanessa Lawrence as “design elements in the way we show things which are not obvious to either the user or the copier. When we see the two versions side by side, we can spot clues.” The Guardian reported that these features were pure design elements such as the width of roads, and did not extend to putting misleading features into the maps themselves, corroborating what Lawrence had claimed: “There are some publishers who put deliberate mistakes in their maps. We don’t do that—it would mislead our customers. For us, it’s more about the style we use.”
