With the publishing of Blocks, people can post their own designs online. If world renowned architects or mechanics decide to post a block for a new roof design or new gear, and there was no testing done on it, if that failed under live load, costing a person their life, what would the reaction be? Someone could also go as far as hack into databases and delete, destroy, or alter the information. If that occurred at a time of human dependence on machines to design and build all our structures, it would lead to chaos. Computers and robots are much easier to manipulate then a person would be.
With AutoCAD, if you could access the enemy database for construction of vehicles and manipulate their designs, you could have them produce inferior vehicles and weapon systems than they would normally use, or even cause such systems to malfunction.