[joshmlewis]

To me it seems like these keys were shared on a site somewhere and when people Googled for free blurity key or whatever these came up.

[eridius]

If that were true the author would have been able to find the keys, but he said Google failed him.

[joshmlewis]

Maybe they didn't search on Google then, but another forum or site that isn't indexed by Google.

[burntwater]

It's possible the serial was posted on a dark net, such as Tor.