You probably haven't investigated, but I'm wondering if any of those are actually what they claim to be, or more likely just malware payloads. It's quite common for the black hats to shotgun-distribute a malware trojan labeled as a crack or serial for thousands or millions of software titles.

(I am resolved to only ever get burned by that once...)

How about getting some help from bloggers? Incentives for them to write about not pirating your software?

Sounds like the esteemed director of search quality at google has his work cut out for him.