as to the original post, Almost of the games I played on my C64 during the 80s were copy protected, but judging from the fact that most of my games were cracked copies back then, CP couldn’t have been that good. You could also get around CP by using specific file copiers that had seperate copy parameters for each game, IIRC.*
As for this part, I have recently heard that some manufacturers are now doing this with games on CD (actually, I heard they are putting a hole in the CD at a specific spot in the CD) and if the CD in the drive doesn’t have the hole, the program will refuse to run, even if you make a perfect image copy of the original CD in question. I cannot vouch for the truth of that info, though.
*Before anyone starts lecturing me about intellectual property rights, I was about 11-16 years old during this period, and was completely unfamiliar with the concept. I do not condone illegal copying of software and do not currently own any illegally copied software…