If it was DURING the test that a single student decrypted the test and handed the answer out to everyone in the class you honestly don't think the teacher would retest them or discipline them and fail the ones that cheated?
After the test was taken, why would it matter if they discovered that the questions had the answers the whole time? They already took it. There's no going back. Sort of a fail analogy. You can't decompile a test in its raw form to find its answers (like the PS3's security) your example is inferring that the teacher wrote some kind of random string of letters or numbers at the bottom of the test, easily seen by the students who can then try to decipher it for answers. That is not at all like the case with the PS3. Geo actually had to break apart the PS3's software, aka decompile.
Students have a choice of either:
1. participating again, and taking the test again, and giving out the same answer, again; or
2. not choose to participate.
Same for Sony. Their key has been revealed. Now you have two choices:
1. use the key to your advantage. Run homebrew software on your PS3. Have the option back of being able to install Linux and other OSes; or
2. not use the key to your advantage.
Sony took away the ability to use other OSes on my PS3. I honestly bought 3 PS3 games ever since the PS3 was released. One game with the system, and two other I bought, one was Heavently Sword and the other was Killzone 2. My original intent was to have the PS3 as a media hub running Linux, have it hooked up to my network, ability to remote-login, use JBOD Raid enclosures, and stream any media onto the TV. Sony took away a huge chunk of the original design of the system, which I paid for. If they took it away, I want a partial refund, because now the product does not do what it used to do before. There are workarounds to do this, i.e. I could use TVersity or its variants, but honestly it was just too much hassle and now PS3 is gathering up dust. I haven't turned it on since then because it's useless to me now. What does Sony have to say to that?
They would have to address MY issue before they pursue THEIR issue because they caused MY issue prior to THEIR issue. Had they kept the ability to install Other OSes, PS3 may remain, to this date, an "uncracked" console system.