You Learn Something New Every Day.

[douglas]

Whoever wrote that is just trying to scare you.

CD Key protection is not generally done by making a long list of valid CD keys and checking the list when you type it in. Instead, any key that passes a particular check, a simple checksum being the simplest, works. CD key generators work because somebody figured out the algorithm used to check keys for that particular program and then used that knowledge to construct an algorithm that randomly generates a key that will pass. No list of valid keys gathered by spyware is necessary for this process.

I suppose some keygens may include spyware, but I'm pretty sure most do nothing more than what they say.

Edit: Games that connect to a central company-provided server may check the CD key used against a database of CD keys actually sold, and prevent any functionality requiring that server from working if the CD key used is not in the database. They may also check for duplicate CD keys and prevent multiples of the same key from connecting at the same time. It could technically be possible for someone to have gotten your CD key by chance from a key generator and prevent you from using the server, but this is extremely unlikely, as the number of keys that pass the installation check is typically several orders of magnitude greater than the number of copies (and keys) actually sold.