In the 90s I worked as an image analyst for an offshore exploration company. It was my job to retrieve, process and analyse images from boreholes relating to geological formations and makeup. I also had to ensure that the image was rotated according to magnetic north. I did the job, ran off the prints complete with direction tadpoles indicating fractures,, holes etc and sent them off to Maersk. A short while later my boss (a nuclear physicist) had the prints rolled out in the conference room with a puzzled look on his face. I explained the processes that I had done to do this job. He looked at me and said that he pre rotated the borehole images before I got them. This meant that Maersk were spending millions looking in the wrong direction. His last words on the matter were that we should keep this to ourselves.