According to statistics from TorrentFreak, by far the most pirated television show of the year is the HBO fantasy epic “Game of Thrones,” based on the hit “A Song of Ice and Fire” series by George R.R. Martin.

Each episode of “Game of Thrones” was downloaded an average 4.28 million times. To put that in perspective, the season 2 finale “Valar Morghulis” was the most widely watched episode of the series on HBO and drew in 4.2 million viewers when it was aired for the first time.

Why are so many people turning to piracy to watch their favorite shows? Of course, for some, it’s simply the convenience and price (free) of illegal downloads. But there are many other issues at work as well.

Many pirates are turning to BitTorrent because of the lack of available legal methods to watch their favorites. Take “Game of Thrones” for example.

By a large margin, Australia had the largest number of illegal downloaders for the fantasy epic, and in Australia, the show airs one week behind the United States. In the age of digital worldwide fanbases, this means that many fans feel the need to pirate their favorite TV show just to keep up with other fans and avoid spoilers.

Watching the show a week behind the Americans means that Australian fans can't participate in online discussions about the show, simply because they can never be up to date through legal means. For many, this problem is easily solved through piracy.

Another big problem with “Game of Thrones” and HBO’s business model is the complete lack of legal ways to watch the show digitally. HBO offers subscribers an online streaming service called HBO Go, which lets users stream HBO shows on their computers or other devices. But it's available only to those with a cable subscription to HBO Go.

An increasingly large number of television fans (mostly those in their 20s and 30s) have been abandoning the physical box in favor of subscription streaming services like Hulu Plus, Netflix, and Amazon Prime. For these users, subscribing to HBO Go in order to watch “Game of Thrones” would mean buying a cable subscription and a premium HBO subscription on top of that.

In some parts of the U.S., that could mean that potential customers would be paying as much as $70 a month just to watch “Game of Thrones” legally each week.

This puts HBO in a curious position. They have a hit product (“Game of Thrones”) and a die-hard fanbase, but no way to legally put their product into the hands of many of these fans.

Here is a complete list of the 10 most pirated television shows below, courtesy of research by TorrentFreak. Numbers are based on average downloads per episode.

  1. “Game of Thrones” — 4.28 million
  2. “Dexter” — 3.85 million
  3. “The Big Bang Theory” — 3.2 million
  4. “How I Met Your Mother” — 2.96 million
  5. “Breaking Bad” — 2.58 million
  6. “The Walking Dead” — 2.55 million
  7. “Homeland” — 2.4 million
  8. “House” — 2.34 million
  9. “Fringe” — 2.28 million
  10. “Revolution” — 2.13 million