The first article is a biased blog on a theory posed by a guy after reading another article that was never actually published but leaked (same study as article 3), the guy posits that if people are completely banned from the internet due to a French anti-piracy act they will spend less in other entertainment venues.
The second article is a biased news story that takes "high piracy of leaked albums by big name artists also correlates to a large number of sales" to mean "Piracy helps sales" ignoring the fact that people might just be pirating popular releases, which is even more likely when the same results are not found by lesser known artists with large pirating numbers.
Third article is a horribly biased blog on a study that was unpublished that was "leaked" to news media from a collection of self reports that asked "Do you pirate" and "how much do you spend online".
Third article is another biased blog on the 3rd's study from a different site.
I'm not going to say piracy is as bad as Hollywood states it is, Rob Reid did a great job of that:
So yeah, piracy isn't that bad, but you'd be a fool to believe piracy is helping the industry, the true question is just how much piracy is killing the industry. How many US anime distributors have gone under since piracy has become more rampant due to increased storage, higher internet speeds, and increase in fansub groups? Couple that with the decrease in Japanese and US sales. Now this does not take into account the burst of the anime bubble in the early to mid 00's, nor does it take into account the slumping economy, but is it such a stretch to believe piracy has not played a large part in the shameful state anime is in right now?