Which means this entire thing can be defeated by Software Cracking 101 - look for the error message that gets triggered when you do the thing you're trying to change, work backwards, and change the JE/JNE assembly instruction or NOP it out.
Somehow I think it's not that simple, but also somehow I think that real counterfeiters will not be deterred by this manner of weak DRM.
It's not meant to deter "real" (professional) counterfeiters -- this, along with the copy machine code, is meant to stop casual counterfeiting. Which is a good thing, as there are quite a number of people who are normally honest, yet could be overcome with a strong enough temptation (getting a free $20 bill), if it appears easy enough.
And of course they will get caught and have their lives ruined. So by making the act of falling into the temptation a bit harder, you are keeping more honest people honest.
Somehow I think it's not that simple, but also somehow I think that real counterfeiters will not be deterred by this manner of weak DRM.