Prior to the premiere of the season 5 of four episodes of show were leaked online.
The leaked episodes were quickly downloaded via various torrent sites.
According to Torrent Freak, HBO is tracking down the people who watched those leaked episodes.
The first copies leaked from a review screener and were quickly spread across public torrent sites and downloaded million of times.
Some reddit users who have downloaded the leaked episodes are reportedly receiving warnings from their ISPs.
No serious legal action is being taken at the moment as HBO doesn't have names of alleged pirates.