The horrible part of this thread is that it makes me feel a bit old. I should grow a beard and stroke it.
First of all, since you seem to be unaware of the field, the specific term for the people who break copy protection is ?crackers? (as in safe crackers; it refers to the art of disarming locks). They?re not a cohesive group of people; I can?t speak for their motivations or employment. As far as I know they range from young to old, hobbiest to veteran, student to millionaire. (This is, however, the exact same skill you need to analyse the most advanced malware. Which uses almost exactly the same techniques.) But hey, some people just like making and solving puzzles--and that?s been going on for three decades now. Frankly it has little to do with piracy; it?s a problem firmly in the security arena.
Secondly, this basic technique is, of course, older than dirt. Captain Blood?s shaky hand. Going to prison because you didn?t know the manual code, four hours in. You can?t open the door without the codewheel in the box. You didn?t know what to do next because that one item wasn?t there. The lever puzzle is actually unsolvable. There?s a million of these, and I know gamers from my generation might recognise one or two of those.
Rob Northen did a lot of the ones I remember most fondly; those, and bizarre disk formats. Honestly there?s a certain charm to them. (I particularly liked the one in Introversion?s sublime ?Uplink?, which deliberately includes a black-on-black code table in a sort of retro nod to them. Bonus points if you recognised on sight the opcodes and ASCII in the table and figure out it?s actually from the program itself. Very meta!) Except maybe word?from?the?manual protection; we?re all very glad that one died. *shudder*
And what are they, deep down? To paraphrase Admiral Ackbar: it?s a trap. A checksum. A ?logic bomb?. They call it a ?hook? because it?s an internal callback to the otherwise?external copy?protection routines that make up 99% of all the DRM you see nowadays. Some of them are obvious. Some are subtle. Some can be downright nasty.
From what I hear, the ?Scene? culture made it into a race; not about the content, but about who gets to smash it first, who gets to distribute it first, who?s fastest uploading on whatever it is they use nowadays. (From what I gather, they definitely do not distribute to the public; it actually leaks to the various public sites afterwards, without their consent. That may be a bit out of date though, I don?t make an effort to keep current on this stuff.) I?d say whoever tripped over this checksum lost this ?race? however, as it?s a bit like running into the hurdles when you?re supposed to jump over them. (It?s been alluded to above that it?s been done properly now; I?m not surprised if that is the case.)
The problem you?re going to get with all of these traps, is the same problem you had with these techniques in the 80s; DRM false positives. False positives are in inevitability in any test and sometimes a very serious problem, and the more sensitive, paranoid and hair-triggered the copy-protection scheme, the more likely those are. Got a double-sided drive on that Atari ST? Then a certain few early games are going to think you copied them even if they?re originals.
And with a trap like this, you?re not going to know right away until the game acts a little buggy.
It?s not really ethical to put traps like this in your code, to be honest with you; you?vre putting bugs in your code on purpose, and the trouble with intentional bugs is if you get bugs in the bits that make the traps fire, they become altogether unintentional again.
In fact, I don?t think I?ve ever actually seen a copy?protection scheme that hasn?t--sooner or later--developed a false positive or two. History is rarely very kind to them. They have no idea what you?re going to try and run them on now let alone in 10 years, but they?re probably not going to like it much. As a result, and because copy protected disks had (and have) a tendency to degrade much quicker than standard ones, a lot of these older games have only survived and been preserved in their cracked forms (which sucks for those who?d like to teach a little security lesson in historical reverse?engineering; what good?s a puzzle someone already solved?). In these publishers? rush to protect the work they?ve invested in (I can recognise their motivation, although I don?t personally agree with their actions), are they guaranteeing it won?t see future generations? What happens when the activation servers go dark on your fancy DRM scheme? What happens when the publisher goes bust?
So it?s best not to rely on these things as foolproof, considering how little control anyone has over the platform they?re run on. Real computers are full of surprises, and not very controlled at all. Overclock a little too much (as some gamers do) and you?ll be surprised how many of these little checksums you might fail because of a single bit error in the wrong place. Perhaps the moderator shouldn?t be so sure of himself. He might well be right in this circumstance (he probably is), but I?ve also seen this exact kind of thing turn around and bite people a lot when it turned out subtle traps were causing serious bugs for legitimate users; for example, one memorable instance in the 80s-90s where a CAD application dongle (naming no names but it begins with an A) started to malfunction, causing the lines to be a bit out in the drawings, but not enough for anyone to notice (until they built the things, they didn?t work, and then they went back to the drawing board and found the drawing board had been deliberately and subtly tampered with by the software because it wrongly thought they were unlicensed?).
Let me conjure up the image of a hypothetical game, being released with an infamous number bugs in it, but it turns out in time that many of those bugs are in fact copy protection hooks, and what is really happening is that the copy protection is bugging out and failing original copies, whereas the cracked copies worked just fine because the logic bombs were disarmed. Does this sound like an unlikely scenario? Would you, as a legitimate customer, be a bit peeved about that? In fact, do you think you may have already seen that?
Quoth the above:
they should release viruses that destroy the computer as the pirated versions
I?ve personally seen one pretty legendary trap that unleashed a bootsector virus if the checksum failed. Really. Yes, it?s not a myth, someone actually did do that once, long ago. And that same bootsector virus became rather widespread because there was a bug in the checksum routine that caused it to run anyway sometimes. Heh. So much for the ?pirate trap?.
You?d go to prison if you pulled a stunt like that today. It was a terrible idea then, and it?s a terrible idea now.