>>717202735
Most cd-keys worked if the game was offline. Even Diablo 2/Warcraft 2 ones (BNE) did work fine for installing
It was mainly done to stop people reselling it since they thought that A, people wouldn't keep the manual/slip with the cd-key and B, if they had online functionality to an account, it would stop people buying it second hand
DRM in terms of piracy wasn't why it was done. It was DRM in terms of protecting money loss