Maybe a few don't know that they are downloading illegally distributed software, but I'm pretty sure most know what they do. While in Poland it might be legal to download music or movies that way, for software its not.
If you need analogy, then perhaps this might be good:
Someone binds another person and puts him on street. Said person got glued to him message on paper saying its okay to "do anal" to him/her, with is obviously not true. Now you can guess that what is written there is a lie put by some criminal, what only dumb/not_from_this_world people wouldn't notice, but either way it doesn't make it legal to pretty much rape said person, just cause someone wrote something. Common sense applies, I'm pretty sure thats what would be pointed out in court.
Besides, there are cases where someone gets convicted to something, just cause he done harm to someone, even if unintentionally. It makes sense, cause people need to take responsibility for their actions.