The task that is difficult in reverse-engineering is the task of making what is in such a way that it will no longer be the same. The fear that is involved has to do with the fact that patent information can be quite sensitive. Copying a product that is under a patent is highly illegal. But, if they can figure out how to use it and make it in a different method, it may fall into the gray area. What is important to remember, though, is that the patent is on the functionality of a product, not necessarily on the way it is designed.
Reverse-engineering is something that has happened the most often by the military. In this case, the reverse-engineering will be used to copy other nation’s technology when it comes to military endeavors. In many cases, the information is obtained by intelligence operations. Reverse-engineering was most commonly used in the Cold War and World War II.
You will find that reverse engineering also happens as a result of curiosity; seeing if they can do it, so to speak. It is also used as a means of cracking the code of security measures and finding a way to get around the security restrictions that can be found in such things as software and electronics. It is quite possibly quite illegal to do these things though and this needs to be taken into consideration.