Americas biggest security s**** up in 1975
America had just finished building its newest Nuclear submarine. It was better than anything Russia had by far. Technologically superior to Russian Nuclear submarines in every conceivable way.
Mattel toys wanted to make a model of this submarine and the designers were excited about making one. The designers provided inside pieces of information about the submarine in a full-color brochure which revealed the inner workings of our top-notch new creation.
It took years but an expensive hard to build plastic model was made. No security officials seemed to notice or care.
The Russians care though and they bought several of these models and sent them to Russia.
The Russians soon knew how to build our submarine and not only did they know, they had a full-scale model of the submarine.
Years later the Russians had one of their own.