GPL's Strength
Morty writes "So, why hasn't the GPL been successfully
challenged yet? In this article, Eben Moglen, General Counsel to the FSF, explains that the GPL is in a stronger legal position than most licenses. Most licenses restrict the user from doing what would otherwise be legal. Because the GPL (and presumably, other free/open software licenses) let the user do things that are otherwise illegal (copy and redistribute software), the GPL is in a stronger position to dictate terms. If the user doesn't accept the terms of the GPL, the default is for copying and redistribution to be forbidden under copyright law. I had never looked at it that way before. . ."
Perhaps my mathematical outlook on life gives me a different definition of the word 'proof'.
The GPL doesn't restrict your use of the software. So you are free to use the software whether you agree with the GPL or not. It is only when you distribute GPLed code that you agree to be bound by its terms.