At first this article reads like your typical anti-piracy screed. It rants about how 10x more people watched GoT illegally (confusing them with lost sales) and ends with how downloading movies can get your credit card stolen.
The middle of the article however, destroys the author's case.
Time Warner (owning company of HBO) CEO Alan Bewkes stated in 2013 how becoming the most illegally streamed show in history was “better than an Emmy” and that torrenting ultimately led to more paid subscriptions.
“We’ve been dealing with this for 20, 30 years—people sharing subs, running wires down the backs of apartment buildings. Our experience is that it leads to more paying subs. I think you’re right that Game of Thrones is the most pirated show in the world and that’s better than an Emmy.”
The CEO of Time Warner, who knows more about the finances of his own show than ForeverGeek writer Tom Llewellyn, championed piracy and said that it brought them more subscribers rather than nearly destroying the show as the article claims.
Needless to say, Tom forwent a rebuttal in favor of writing how you can get malware from downloading it...
Anti-Piracy Propaganda: 0
Truth: 1
The same way you know how many times a show was watched legitimately, you take a sample of known data and extrapolate it from there. It's basically guesswork but it's educated guesswork.
BitTorrent, even though it's decentralised, is still operating on the public internet using public, known protocols. You can join a swarm and get an idea of how big that swarm is with a small amount of data inspection. I mean, your torrent client knows how many seeders and leechers there are, right? Just watch the swarms and extrapolate from there.
Any time you read these articles, they're always caveated with something similar to "The number could be much higher than that" too because it's not just torrents, you've got newsgroups, file shares, streaming sites, even old school IRC, people putting titles on a USB stick and so on. Hence there's a lot of guessing, but it's not entirely plucked from thin air.
Where it does get more bullshitty is when they try to translate those numbers into lost sales. That is just made up numbers as far as I'm concerned.