There were tons of issues with earlier DRM models. SecuROM not working with certain disc drives, SafeDisc driver vulnerabilities, StarForce allegedly bricking some hardware, Tages eating up online activations for simple hardware swaps. Everyone hated them, but the Sony rootkit was probably the biggest one at the time. From what I remember there was no mention of it anywhere on the CDs or in the EULA, and when they did get caught their "fix" basically just hid the files while collecting info on you and sending it back to Sony.