Curiouser and curiouser. Is it a violation, I wonder, if someone picks up a pencil and draws one of these from memory, after having seen it on the six o'clock news? if so, the world must be insane.

You hit the nail right on the head.   Taking the corporate "logic" to its limits, which isn't a very long journey, they actually ought to consider that drawing from memory is a violation (which wouldn't make the attitude less curious, by any means).   Likewise, when anyone manages to get a photo of a jet blasting over the hillsides, that should (by the same corporate "logic") be considered a violation, too.   The only difference between the pencilled-sketch and the photo, on the one hand, and the 3D model, on the other, is that the model ends up on the internet, on predictable sites, where the lawyers can find it easily.   I suppose that you can add to that the fact that a 3D model does look, to the uninitiated, quite technical, even when it isn't, for real-world purposes.    No lawyer wants to have to convince a jury that some inept scribble, that looks roughly half-way between a VTOL Harrier and a harrier of one of the various species of the genus Circus, realistically presents any threat to security.   This shows up the hypocrisy of the whole policy.