This wasn't an anti-piracy measure. The game was free to play, but they uploaded it to sites such as The Pirate Bay to distribute it. They mention that people

This wasn't an anti-piracy measure. The game was free to play, but they uploaded it to sites such as The Pirate Bay to distribute it. They mention that people have been put off by the game due to the large file size (excess of 500mb, I think) which is generally not a daunting feature to those who use torrents. The didn't really fool anyone, per se... they just took advantage of distribution channels.