Not necessarily looking to go in the direction you mention, but I'm curious what you mean nonetheless - AFAIK, Skype's consumer/personal offering is free, and then you need to subscribe for business accounts because that all runs on microsoft servers.
Are you referring to a different product, or are there copies of old enterprise skype server systems floating around out there?
Sorry - I think there's been a misunderstanding. I was referring to the context you mentioned in the latter half of your comment, and the supporting circumstances for that.
(In other words, I'm not aware of any way Skype can be pirated, and I'm not particularly aware of any, err, accessible commercial alternatives.)
Are you referring to a different product, or are there copies of old enterprise skype server systems floating around out there?