Sony didn't accidentally give out the answer to their encryption. It took years for anyone to find the answer. Completely different example you're throwing there.
They DID accidentally give out the key. You mean if it was not accident, they gave it away intentionally?
It took years because we didn't know where and what to look for.
Sony didn't certainly INTENTIONALLY use their master key in every single polynomial equations. It was ACCIDENT, or better put, it was POORLY designed. Its inherent nature is that once you have the key (or know where to look for) you can use the key to open anything and everything else.
Lets say the teachers ACCIDENTALLY (or unknowingly) put the answers along with the questions, but only in "coded" form that teachers use amongst each other to communicate. Does that change the situation even a little bit? NO. Most of the students didn't know that the answers were right there because it didn't look like answers, but some of the students, after years, finally figured out what the "code" was and therefore got access to the answers. Are the students "cheating?" Or is it the fault of the teachers for leaking the code? Are you going to hold accountable that ONE student who figured out the code?
What about those early adopters (i.e. me) who bought the PS3 because it could install other OS? And then Sony decided to take it away? I understand in EULA it states that Sony may change the intended use of the hardware whenever they see fit, but really is that fair? I just lost a part of the function I bought the original hardware for, therefore removal of such feature should entitle me to a fraction of the value of the hardware that I paid for.
Why do you not realize this?
Also if you look at closely at ANY EULAs and followed it, you'd be breaking their Agreement (NOT LAW) if you ever flashed any piece of hard with any custom firmware. Is my router company going to sue the person who came up with a custom firmware that is perhaps better than the stock firmware they put out on the market?