Is there one particular software you want answers on?
I have some valuable experience with the answers to this, related to several different software, but I'm not into typing out all the different answers right now.
Generally I would disagree with the above statement. Obviously if you get ripped off, then it's a bad idea, however if you get someone from here who has the real deal to part with... the steps to make it legal are minimal IMO. (for the software I know about... Adobe, or flexi, or Estimate... etc)